Merge pull request #36 from shalabhc/master

Add ~/.howl/bundles to bundles dirs
Document search commands in manual
C: Fix lexing of 'double'
Moonscript: Don't lex eol as part of a line comment
Aullar test theme: Specify some different font sizes for headers
aullar - Styling: Add support for on demand re-lexing
Fix display block x offset handling
Aullar: Add re-lexing as you type

Includes various other display corruption fixes.
Correctly release background buffer
Add the option of specifying a specific shell for Processes
exec and project-exec commands now uses the user's shell
Site: Check for empty packages when slicing for columns
Bind exec and project-exec commands to keys
Command input: Fix cd with '..'

Also don't insert the current directory as a completion if
it's the current directory in the prompt.