Add conf filetype, for generic Unix configuration files

We set the "ini" filetype for files ending in one of "repo", "ini",
"cfg", "properties" or "desktop".  Most of these actually use Unix
style comments (#) instead of DOS INI comments (;).

Introduce filetype "conf" which is similar to "ini" except it uses the
default # as comment_line string.  Both Vim and Emacs have a filetype
(or Major mode) named "conf" (hence modeline-parse of "vim ft=conf"
will work).

Here are references that show that the new "conf" files use #-comments:
*.repo -- search for # in
    https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/deployment_guide/sec-configuring_yum_and_yum_repositories
*.cfg: don't know much about this one, but at least the motivating file uses #
    https://github.com/buildout/buildout/blob/master/buildout.cfg
*.properties files:
    https://en.wikipedia.org/wiki/.properties
*.desktop: per spec
    https://specifications.freedesktop.org/desktop-entry-spec/latest/ar01s03.html#comments

rc/filetype/conf.kak

@@ -0,0 +1,23 @@
+hook global BufCreate .+\.(repo|cfg|properties|desktop) %{
+    set-option buffer filetype conf
+}
+
+hook global WinSetOption filetype=conf %{
+    require-module conf
+}
+
+hook -group conf-highlight global WinSetOption filetype=conf %{
+    add-highlighter window/conf ref conf
+    hook -once -always window WinSetOption filetype=.* %{ remove-highlighter window/conf }
+}
+
+provide-module conf %{
+
+add-highlighter shared/conf regions
+add-highlighter shared/conf/code default-region group
+add-highlighter shared/conf/comment region '(^|\h)\K#' $ fill comment
+
+add-highlighter shared/conf/code/ regex "(?S)^\h*(\[.+?\])\h*$" 1:title
+add-highlighter shared/conf/code/ regex "^\h*([^\[][^=\n]*)=([^\n]*)" 1:variable 2:value
+
+}

rc/filetype/ini.kak

@@ -1,4 +1,4 @@
-hook global BufCreate .+\.(repo|ini|cfg|properties|desktop) %{
+hook global BufCreate .+\.ini %{
     set-option buffer filetype ini
 }