add more blank lines for readability
ignore `build` dir in repos
do not use short name for augroup
add custom commands to lesscss

This allow define options to less compiler for reuse. For example,

     let g:lesscss_commands = {
        'compress': {'g:lesscss_cmd': '$(which lessc) --compress -01'}
     }

And then `:Lesscss compress` to run with predefined options.
add `compress` and `uncompress` command to defaults
add completion to registered lesscss commands
less error prone path to less compiler
write function documentation before function itself
move command definition to corresponding function
use defined function to show plugin state
silent command as echo messages in pipeline is meaningless

The :Lesscss silences pipeline output at whole and no messages showed to user.
apply options in separate function
add documentation to Vim
remove all autocommands if plugin disabled but keep augroup
remove code duplication
allow rebind toggle plugin key
fix 'vim_lesscss' default value in documentation
add functions to on/off plugin
less tricky init at startup
use default options if command skipped