list pending entries (for all kinds of releases)
2 fixes to StdlibPending::GetEntries()

First, explictly require semver. Second, do not delete downgrade
entries, as they may be allowed by config. To do so, also require
stdlib configuration.
change StdlibPending::GetEntries()

Instead of a fixed release version, just pass the
release update type as argument. Adjust all calls
to the method accordingly.
add 2 filters to pending list

Can now filter by the item update type
and the release update type which the
pending change can go in.
implement editing the pending item's changelog comment
add method to bump a semver version
Revert "change StdlibPending::GetEntries()"

This reverts commit 1ec02cf2507e74fc4b773feccb16aebd5598b23c.
Adjust list of pending items to commit 8ddbaf186e

The mentioned commit changed StdlibPending::GetEntries() back to
accepting a release instead of a UpdateType constant as argument.
To get the matching release version for a given update type, use
the new UpdateType::bumpVersion() introduced in commit 80fdd3bd3f.
implement delay handling

Add a new DB attribute 'delay'. It can be set via
StdlibPending::SetDelay(). Also obey the delay in
StdlibPending::GetEntries($release) and output it
in StdlibPending::GetAllEntries();
Add new 'release' filter to pending list

Commit b0351f66a9 made it possible to specify a specific release
instead of just an update type. This makes it possible to enlist
delayed items even if they are delayed for several major version
steps from the current version.
add API for delaying a pending item
Merge pull request #28 from maul-esel/stdlib-pending

Add handling for pending stdlib changes