altered layout of settings-view

added an additional width-50 + fltlft/fltrt to have it show 2 columns
instead of 1.
fix month nav category/venue calendar front (#589, #605)

create url self instead of using JEMHelperRoute
Merge branch 'master' of https://github.com/jemproject/JEM-Project
Added check for Joomla 3

Added check to see if it's installed in J2.5 and if so if it's from
version 2.5.6.  If not the installer will abort.
changed default-value FormatDateShort

this as it looks nicer in the table.
renamed references of article
altered some language strings (backend)
altered eventelement, REF #608
replaced com_jem_go by the internal language-string + cleanup, some fews
removed unpublish/archive/trashed from publish options, REF #608
changed category-element a bit
altered category-venue-event elements
renamed com-jem-go to  Jsearch_filter_submit
renamed com_jem_reset to Jsearch_filter_Clear
increased version nr
increased copyright date component
increasing versionnr + copyright date modules/plugins
increased versionnr
added itemId to UserstateFromRequest (venue-view), REF #521
fix categories view event table (issue #610)

- $this->categoryid must be $this->catrow->id
- $row->odd was undefined so use local $row