Fix two minor documentation mistakes.
Fixed the documentation of clear()
Added an entry to changes.h
Fixed indentation
Merge pull request #235 from alrashedf/master

Fixed an indentation problem
Merge pull request #232 from bangerth/doc-fixes-10

Fix two minor documentation mistakes.
Added clear() to TableHandler
Fixed the documentation of clear()
Added an entry to changes.h
Fixed indentation
Fix two minor documentation mistakes.
Merge remote-tracking branch 'upstream/master'
Added get_lap_time() to Timer which returns the time taken between the last start()/stop() cycle.