Some little details for better cross-os

- Better mysql & postgres support.
- Associative arrays are evil in bash.
- Better launch of browser for macosx.
Switching from wget to curl as the former one is not included in OSx by default

Also adding an option to specify
an alternative php command.
README - Adding more info about requirements
Show perf. info only through web access
Hide most of the outputs and change them for informative messages

Also:
- Removed debug var
- Solved curl issues
- Stop execution if something goes wrong
  in compare.sh
- User UI runs properly ordered
- Solved issue getting the session size in
  master (it was not getting info when the
  session handler was specified