In kde4 times, the layout of clock's tooltip was nicely arranged using a
table. Now it's a bit of a mess so this brings back some nice layout.
Also simplifies the timeForZone function which is used only for the
tooltip.
BUG: 357005
BUG: 351472
CCBUG: 357004
FIXED-IN: 5.6.0
REVIEW: 124047
Adds a simple QSortFilterProxyModel on top of TimeZonesModel and
reimplements filterAcceptsRow using QStringMatcher (supposedly faster
according to qtdocs).
REVIEW: 123740
BUG: 346681
FIXED-IN: 5.3.1
Not all zones have '/' so the splitting may not result in list of two
entries. Use last() instead of at(1) to avoid possible out of bounds
assert.
BUG: 339411
Still has couple missing features:
* no time in the tooltip yet (needs larger refactor)
* no order selection
* no default timezone (but last used is always saved)
* couple minor issues
REVIEW: 120314
CCBUG: 337564