Clean up the phpDoc of t3lib/mail/

So I made a patch doing mostly:

* Provide correct parameter names in phpDoc
* Provide correct data types in phpDoc
* CGLify phpDoc (remove tabs)
* CGLify method signatures (the first line of the method)

Change-Id: Ie2844aa5528f7d351f497506e3c32d89d209ced8
Resolves: #37590
Releases: 6.0
Reviewed-on: http://review.typo3.org/11708
Reviewed-by: Oliver Klee
Reviewed-by: Georg Ringer
Tested-by: Georg Ringer