Test for PHP >= 5.2.0
Use password_hash() if possible

It provides a future proof interface to stronger password hashes than plain MD5.
Unfortunately it's a rather new feature (PHP 5.5), so use MD5 as a fallback.
(A future change might import the password_hash polyfill that works with >= 5.3.7)

The change also avoids a possible lock-out bug in case passwords were entered with
leading or trailing spaces by handling password hashing the same everywhere.
Add password_hash polyfill

This allows using password_hash with php >= 5.3.7
(or even earlier with a certain feature backported)
Merge pull request #8 from pgeorgi/version-test

Test for PHP >= 5.2.0
Merge pull request #9 from pgeorgi/password-hashes

Use password_hash() if possible
(Cal) Fix iCal format and anonymous view
Merge pull request #7 from pgeorgi/db

Remove direct mysqli use
(CW) Bugfix creating wiki categories
Merge branch 'master' of https://github.com/churchtools/churchtools_basic
(CR) Bugfix Date exceptions and additions für Resources from Calender
Sort filenames and some minor layout optimizations