`x` is often criticized as hard to predict due to its slightly complex
behaviour of selecting next line if the current one is fully selected.
Change `x` to use the previous `<a-x>` behaviour, and change `<a-x>` to
trim to fully selected lines as `<a-X>` did.
Adapt existing indentation script to the new behaviour
Some languages have a trim-indent command but don't use it (for no
apparent reason). Make them trim trailing spaces when exiting insert
mode, like most other languages support scripts do.
Correctly indentint on "end" keyword seems very hard,
it is simpler to remove it. And we already insert "end"
in ruby-insert-on-new-line hook, so the removal shouldn't
hurt too much.
The syntax highlighting has been broken down into 3 main categories:
string: string, array of words
variable: symbol, array of symbols
meta: regexp, shell execution
In Ruby, identifiers can end with a `!` or `?` too, which means that `class!` or `end?`are not actually keywords, but regular identifiers. This fixes that by not using `\b` but `[^0-9A-Za-z_!?]` instead in some places.
This commit allows using the <semicolon> expansion in commands, instead
of `\;`.
It makes commands look more elegant, and prevents new-comers from
falling into the trap of using <a-;> without escaping the semicolon.
