Fix a typo in the regex trying to understand the command.

This is almost certainly not trying to replace 's' characters in a command and is, instead, meant to check for nested properties on bower.commands that were not found in bower.abbreviations for some reason. The kicker is that bower.abbreviations already contains the full command names in addition to the shortened ones, so this code path ("Direct lookup") probably never actually results in finding anything and can probably safely be removed.
Merge pull request #1151 from eventualbuddha/fix-regex-typo

Fix a typo in the regex trying to understand the command.
Remove Node 0.8 compatibility. Closes #1154
First port of code from checkbower, starting work on #1014
Providing tests for bower-validate command, relates to #1014
Added support to absolute paths as an argument, relates to #1014
Added help messages for bower validate command, relates to #1014
Added tests for missing properties, relates to #1014