Made php optional

Made php optional by checking if php is installed when installing apache or nginx. Also removed some Trailingspace and empty comment lines from php.sh and Vagrantfile. #227

**WIP**
Still Work In Progress and needs some more testing. I also think some scripts will need a php check, cause it could assume php was installed.

edit:
I added a php check (that will exit the script if it's not installed to):
- [x] laravel.sh
- [x] symfony.sh
- [x] composer.sh
- [x] mssql.sh
- [x] mailcatcher (it wont reload php if it's not installed) (Also it seems that only apache is restarted? Nothing special needed for nginx?)

There are 2 other scripts of wish I am not sure if they are depended on php:
- ~~elastichq.sh~~ (As far as I can see this doesn't need PHP, but it does contain a Nginx configuration that enables php?)
- ~~hvvm.sh~~ (Nope doesn't need PHP, but this doesn't work anyways)

~~I haven't tested it yet. Will do that now :).~~

**Update**
*I think it's ready*