Current solution makes it difficult to use common Lua practices of having one-liner if statements and using anonymous functions.
New solution prevents auto-indentation and end insertion, if the previous line contains an "end" keyword.
It does not attempt to match each structure with corresponding end, since using multiple end keywords in single line is a very rare occurance in Lua.
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.
