First work on sorting support for item listing
move most of sorting logic to separate file
support user sorting

Allowed sorting fields so far are 'name' and 'joined'.
fix regression: include rating if it is used for sorting
fix sorting according to rating

Use the same complicate SQL query for sorting as for filtering.
Move it to a constant definition.
Merge branch 'master' into sorting
move common sorting code to new SortHelper class
implement sorting for suspension list

Allow sorting by "created" and "expires". As the list is retrieved
by the Suspension class and not in users/suspensions/list directly,
this implementation slightly differs from the previous ones.
fix item list version sorting to obey semver

As MySQL does not allow custom comparison functions, this is a
little complicated:

- Add 3 stored MySQL functions / procedures that collect all compare
  and sort the required semver data.
- Then add a method to SortHelper that collects the necessary data
  beforehand and stores it in a temporary MySQL table.
- Last, fix items/list.php to allow multiple table joins and use one
  to sort by version.
Merge branch 'master' into sorting

Merge recent stdlib fixes to allow implementation of sort support for stdlib.
item list sorting: remove literal DB table name
Fix SortHelper for columns with different names

MySQLs 'CREATE TABLE ... SELECT' uses the source column names in
the destination table. To make the column names of the temporary
table independent from the source, use 'AS' to change the name.
add sorting support for stdlib release listing

Just as with suspension sorting, the logic is split between
stdlib/releases/list and the StdlibRelease class. Also take
semver into account when sorting by release version.
support sorting by creation and approval date for candidates
enable sorting support for candidate voting output
Add sort support for stdlib/items

Can now sort by name and version.
support prerelease and build parts when comparing semver
Merge pull request #24 from maul-esel/sorting

Support sorting parameters