[ticket/11852] Split filesystem and path_helper into 2 classes

PHPBB3-11852
[ticket/11852] Move tests to folder with new class name

PHPBB3-11852
[ticket/11852] Add class file

PHPBB3-11852
[ticket/11876] Move checksum generation from build PHP files to phing build.xml

This also removes paths from the checksum files.

PHPBB3-11876
[ticket/11876] Replace MD5 with SHA256.

PHPBB3-11876
Merge branch 'develop-olympus' into develop

* develop-olympus:
  [ticket/11876] Replace MD5 with SHA256.
  [ticket/11876] Move checksum generation from build PHP files to phing build.xml
Merge pull request #1735 from nickvergessen/ticket/11852

Ticket/11852 filesystem class must not depend on a web request
[ticket/11878] Missing leading \ in dependencies in soft_delete_mcp_modules

PHPBB3-11878
Merge pull request #1744 from EXreaction/ticket/11878

[ticket/11878] Missing leading \ in dependencies in soft_delete_mcp_modules
[ticket/11879] Replace .live() with .on()

PHPBB3-11879
Merge remote-tracking branch 'cyberalien/ticket/11879' into develop-olympus

* cyberalien/ticket/11879:
  [ticket/11879] Replace .live() with .on()
Merge branch 'develop-olympus' into develop

* develop-olympus:
  [ticket/11879] Replace .live() with .on()

Conflicts:
	phpBB/styles/prosilver/template/forum_fn.js