Merge pull request #528 from Hoffi1/master

Update of Event/Mailer/JEM/Script.php + update sql
Update jem.php

removed echo
removed echo
ACL view access

Support Joomla access levels instead of single gid (site, modules,
plugins)
fix archive button creation

Don't create output if no url etc. has created (archivebutton and
editbutton).
Merge branch 'feature/read-access-j25' into develop
try to merge Hoffi1/develop into jemproject/development
Merge pull request #534 from Hoffi1/develop

More things for 1.9.5: ACL view access + archive button fix
Merge pull request #533 from jemproject/development

Nice fixes/enhancements from Hoffi for JEM 1.9.5
  - delete obsolete files on update (issue #275)
  - alter catids and myattending url in menu table and catids in module table when crossing 1.9.4 -> 1.9.5 border
  - correct mailer plugin (issue #522)
  - change 'el*' to 'jem*' in search plugin to allow searching in EL and JEM at same time
  - ACL view access - support Joomla access levels instead of single gid
  - fix archive button creation (in case old events are not configured to move into archive)
Added mod_teaser to package xml file
Cleaned code #514
Added new modules to package description
Fixed list ordering when sorting by date #509
Fix indentation, cleanup
Various fixes in Help section:
- Removed gmapsoverlay from credits
- Removed "ACL not yet implemented"
- Fixed numerous Typos
- Fixed several HTML validation errors
Fixed image links from absolute to relative paths.
Did not work with Joomla installations in subdirectories.
Removed width/height attributes
Shortened and cleaned up help CSS file
Add .pointer block to jem.css - issue #537
insert legend "Recurrence"
Help section HTML changes
Cleanup, fixing errors, etc