ice - fixed sha1 hash

Old hash was incorrect.
libewf - fixed download link and env

Fixed download link (was no longer available at old location) and also set env to std.
fswatch - new formula

Added fswatch, a handy osx analog of ionotify to watch for filesystem changes and then execute a script.
perl518 - new formula

No idea why there isn't a formula for perl518. I grabbed this from https://github.com/zsmizzle/homebrew-versions/blob/perl518/perl518.rb
fswatch-stdout - alternate version of fswatch

Alternate version of fswatch that outputs changed paths to STDOUT
Merge remote-tracking branch 'fork/fswatch'
Merge remote-tracking branch 'fork/fswatch-stdout'
Merge remote-tracking branch 'fork/ice'
Merge remote-tracking branch 'fork/libewf'
Merge remote-tracking branch 'fork/perl518'