Added support for implied dt-end when only a time is specified.
Added PHPunit tests.
Closes #43
Added function convertTimeFormat() to convert from HH:MMpm variants to HH:MM.
Added PHPunit tests.
Merge remote-tracking branch 'upstream/master'

Conflicts:
	tests/Mf2/ParseDTTest.php
Fixed convertTimeFormat() regex to not capture the colon before seconds.
Fixed unit test assertion.
Removed comments.
Fixed implied dt-end for non-value-class mf2.
This makes @barnabywalters test "testImpliedDTEndUsingNonValueClassDTStart" pass.
Merge pull request #46 from gRegorLove/master

Fix for implied dt-end and a failing unit test