[ticket/11186] Database unit tests fail on windows using sqlite2

The problem is, that we try to recreate the db and reconnect to it, while the
old connection is still hold. To resolve this, we just drop all tables and
recreate the tables instead of the hole db.

PHPBB3-11186
[ticket/11190] Functional tests purge cache before running.

Added functions to get and purge cache to functional framework also.

PHPBB3-11190
[ticket/11192] Add Tebibyte to get_formatted_filesize().

PHPBB3-11192
[ticket/10879] Remove arrow icon from attachment link in editor

If you upload a file with a long filename the filename will partially
cover the arrow icon background image. Remove the icon as it's not needed
anyways.

PHPBB3-10879
Merge remote-tracking branch 'marc1706/ticket/10879' into develop-olympus

* marc1706/ticket/10879:
  [ticket/10879] Remove arrow icon from attachment link in editor
[ticket/11202] Add a heuristic function to check for response success.

This tries to account for php sending fatal errors with 200 status code.

PHPBB3-11202
[ticket/11202] Check response success before content assertions.

This does not change tests that perform requests which are either
clearly not supposed to succeed or are a gray area.

PHPBB3-11202
[ticket/11202] Custom message does not make sense here, delete it.

PHPBB3-11202
Merge PR #1069 branch 'Fyorl/ticket/11190' into develop-olympus

* Fyorl/ticket/11190:
  [ticket/11190] Functional tests purge cache before running.
Merge remote-tracking branch 'p/ticket/11202-olympus' into develop-olympus

* p/ticket/11202-olympus:
  [ticket/11202] Custom message does not make sense here, delete it.
  [ticket/11202] Check response success before content assertions.
  [ticket/11202] Add a heuristic function to check for response success.
Merge PR #1060 branch 'nickvergessen/ticket/11186' into develop-olympus

* nickvergessen/ticket/11186:
  [ticket/11186] Database unit tests fail on windows using sqlite2
[ticket/11192] Add tests.

PHPBB3-11192
[ticket/11192] Also test powers of 10 / 1000.

PHPBB3-11192
[ticket/11192] Also test strings, e.g. sums returned by the database.

PHPBB3-11192
[ticket/11192] Test strings not converted to int/float before.

PHPBB3-11192
[ticket/11192] Mark negative byte numbers as unsupported.

PHPBB3-11192
[ticket/11192] Update $value parameter description to support other types.

PHPBB3-11192
[ticket/11192] Merge dataProvider arrays because the test is the same now.

PHPBB3-11192
Merge PR #1074 branch 'bantu/ticket/11192' into develop-olympus

* bantu/ticket/11192:
  [ticket/11192] Merge dataProvider arrays because the test is the same now.
  [ticket/11192] Update $value parameter description to support other types.
  [ticket/11192] Mark negative byte numbers as unsupported.
  [ticket/11192] Test strings not converted to int/float before.
  [ticket/11192] Also test strings, e.g. sums returned by the database.
  [ticket/11192] Also test powers of 10 / 1000.
  [ticket/11192] Add tests.
  [ticket/11192] Add Tebibyte to get_formatted_filesize().
[ticket/11219] Update sequence values after loading fixtures

If a value is provide for an auto_increment type of column, certain DBMSes
do not update their internal sequencers. If a row is inserted later, it can
be given an ID that is already in use, resulting in an error. The database
test cases now resynchronise the sequencers before the tests are run.

PHPBB3-11219