corrected issue where batch upload stops after 9th image uploaded

* UploadHandler.php and MappingPhpAdapter.php were still using only Title::makeTitleSafe(),
  which has a problem creating a title like,
  'Pantser Rups Tegen Luchtdoelen [PRTL] rupsvoertuig, met twee kanonnen 35 x 228' or
  'GWToolset:Metadata Mappings/Dan-nl/Rijksmuseum.json'.

  using \GWToolset\getTitle() and \GWToolset\stripIllegalTitleChars() took care
  of the issue.

* while troubleshooting this issue i had to watch the job queue in a terminal window and
  noticed that while UploadMetadataJob.php was using error_log() to output any errors,
  Job.php prefers setting $this->setLastError().

* included some cosmetic changes
  - added line breaks to code that is > 100 characters
  - adjusted some documentation
  - re-ordered some code

* re: ticket #173 in assembla - Batch upload stops after 9th image uploaded

Change-Id: I6dbd89482bdfa9e25339d66d41b42644c6d62994