Refactoring: use math expressions (( )) instead of [[ ]]
Refactoring: use math expressions (( )) instead of [[ ]]

When testing for LP features (LP_ENABLE_ options checks), use arithmetic
expression instead of classical test expressions.
Example:
   before:    [[ "$LP_ENABLE_GIT" != 1 ]] && return
   after:     (( LP_ENABLE_GIT )) || return

joshuarubin/dotfiles,tsbarnes/liquidprompt,dan-cleinmark/liquidprompt,joshuarubin/dotfiles,pkkolos/liquidprompt,joshuarubin/dotfiles,nojhan/liquidprompt,milouse/liquidprompt,dpilone/liquidprompt,alexprengere/liquidprompt,dtschan/liquidprompt,laurentbardin/liquidprompt,smadhueagle/liquidprompt,joshuarubin/dotfiles,jaesivsm/liquidprompt,BobHood/liquidprompt