Fix dropdownLinkColorActive to match original twitter/bootstrap

See https://github.com/twitter/bootstrap/blob/master/less/variables.less#L129 - must have been mistranslated. This was reported in thomas-mcdonald/bootstrap-sass#282
update javascript files to v2.3.0
update docs to v2.3.0
update symlinks and rake task to v2.3.0
update sass files to match bootstrap v2.3.0
update Gemfile.lock to latest sass version 3.2.5
build bootstrap v2.3.0 from SASS files
fix typo in include
generate bootstrap form sass files
fix :focus state in mixin buttonBackground

&:focus is missing on line 502, so buttons look broken on focus
update javascript files to v2.3.1
update docs to v2.3.1
update documentation to v2.3.1
update built css files and documentation
customize composer.json
document Composer installation
prefix sass section in readme
capitalize Composer, for consistency's sake
fix huge grammar mistake
Describe Composer

This way, non-php developers won't waste too much time looking into it.