Remove remaining references to boost from documentation/contrib files

README.asciidoc

@@ -104,7 +104,6 @@ Kakoune dependencies are:
 
  * A {cpp}14 compliant compiler (GCC >= 5 or clang >= 3.9) along with its
    associated {cpp} standard library (libstdc{pp} or libc{pp})
- * boost (>= 1.50)
  * ncurses with wide-characters support (>= 5.3, generally referred to as libncursesw)
  * asciidoc (for the `a2k` tool), to generate man pages
 
@@ -207,12 +206,12 @@ sudo zypper install kakoune
 Building on Ubuntu 16.04.
 Make sure you have .local/bin in your path to make the kak binary available from your shell.
 
---------------------------------------------------------------------------
-sudo apt install libncursesw5-dev libboost-regex-dev asciidoc libboost-dev
+----------------------------------------------------------------
+sudo apt install libncursesw5-dev asciidoc
 git clone https://github.com/mawww/kakoune.git && cd kakoune/src
 make
 PREFIX=$HOME/.local make install
---------------------------------------------------------------------------
+----------------------------------------------------------------
 ====
 
 Running
@@ -1169,9 +1168,8 @@ Kakoune trying to be smart.
 Regex syntax
 ~~~~~~~~~~~~
 
-The regex syntax supported by Kakoune is the Perl syntax currently provided
-by Boost :
-http://www.boost.org/doc/libs/release/libs/regex/doc/html/boost_regex/syntax/perl_syntax.html[Perl Regular Expression Syntax].
+The regex syntax based on the ECMAScript regex syntax, documentation can be
+accessed through `:doc regex`
 
 Exec and Eval
 ~~~~~~~~~~~~~

contrib/Tupfile

@@ -35,15 +35,15 @@ ifeq ($(static),yes)
 endif
 
 ifeq (@(TUP_PLATFORM),macosx)
-	LIBS += -lncurses -lboost_regex-mt
+	LIBS += -lncurses
 	CPPFLAGS += -I/usr/local/opt/ncurses/include
 	LDFLAGS += -L/usr/local/opt/ncurses/lib
 else
 	ifeq (@(TUP_PLATFORM),win32)
-		LIBS += -lncursesw -lboost_regex -ldbghelp
+		LIBS += -lncursesw -ldbghelp
 		CPPFLAGS += -D_XOPEN_SOURCE=700
 	else
-		LIBS += -lncursesw -lboost_regex
+		LIBS += -lncursesw
 		CPPFLAGS += -I/usr/include/ncursesw
 
 		ifeq ($(CXX),g++)

contrib/kakoune.rb

@@ -4,7 +4,6 @@ class Kakoune < Formula
   homepage "https://github.com/mawww/kakoune"
   head "https://github.com/mawww/kakoune.git"
 
-  depends_on 'boost'
   depends_on 'docbook-xsl' => :build
   depends_on 'ncurses' => [:build, :recommended]
   depends_on 'asciidoc' => [:build, 'with-docbook-xsl']

contrib/kakoune.spec

@@ -7,10 +7,8 @@ License:        Unlicense
 URL:            http://kakoune.org/
 Source0:        kakoune-84f62e6f.tar
 
-BuildRequires:  boost-devel >= 1.50
 BuildRequires:  ncurses-devel >= 5.3
 BuildRequires:  asciidoc
-Requires:       boost >= 1.50
 Requires:       ncurses-libs >= 5.3
 
 %description

doc/coding-style.asciidoc

@@ -5,10 +5,6 @@ Kakoune is written in C++11, here are the main coding style points:
 
  * Avoid external dependencies besides posix/stdc++/ncurses
 
-   - That means avoid depending on boost, it is only allowed for the regex
-     implementation. The reference for the current regex support is available under
-     http://www.boost.org/doc/libs/release/libs/regex/doc/html/boost_regex/syntax/perl_syntax.html[Perl Regular Expression Syntax].
-
  * 4 spaces for indentation, no tabs
 
  * public interface before private methods/data when defining a class

doc/manpages/faq.asciidoc

@@ -22,15 +22,6 @@ project to this operating system is pretty low.
 Moreover, you can get pretty decent performance by using Kakoune on Cygwin
 (which is officially supported).
 
-Can you get rid of the `boost` dependency and just use std::regex ?
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-The `boost-regex` library provides use with several features that are heavily
-relied upon across several core scripts, and a few of them are not available
-in the standard `std::regex` implementations. Therefore, until the standard
-catches up with `boost` in terms of features, the latter will remain a hard
--mandatory- dependency.
-
 Kakoune is very slow on big files, what can I do about it ?
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -48,10 +39,7 @@ Can I use Kakoune as a pager ?
 
 Kakoune can be used as a pager, either by setting the `PAGER` environment
 variable to `kak`, or by writing data directly to its standard input using a
-shell pipeline. However, since the program relies on several heavy dynamic
-libraries (`boost` being one of them), it will be slightly less practical
-than other regular pagers (such as `less` or `more`) which have a minimal
-amount of runtime dependencies.
+shell pipeline.
 
 Are there any non-console based frontends available ?
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~