added support for opening browsers on osx

modules/osx/init.zsh

@@ -19,3 +19,10 @@ alias cdf='cd "$(pfd)"'
 
 # Pushes directory to the current Finder directory.
 alias pushdf='pushd "$(pfd)"'
+
+# aliases to browsers
+alias canary='open -a "Google Chrome Canary" $*'
+alias chrome='open -a "Google Chrome" $*'
+alias firefox='open -a "Firefox" $*'
+alias safari='open -a "Safari" $*'
+