LTMPlot fix baseline setting

.. it was lost when fixing bar style drawing.
.. maybe we should also allow fill under curves?
Merge branch 'master' of github.com:/GoldenCheetah/GoldenCheetah
UI Nits: QSplitter cosmetics

.. prettified on a Mac.
.. still need to work on icons
Fixup sidebar cosmetics for Linux

.. embossed offset is 2 there too.
UI Nits: QSplitter colors on Linux

.. just adjusted to be more Gnome friendly.
UI Nits: Splitter icons adjust

The icons are adjusted via utility function iconFromPNG()
which currently just adjusts the icon color to be a muted
gray as opposed to black.

This is the first pass at recreating the 'template' function
used by the cocoa image functions. Will add an emboss feature
later, but at least now they are less vibrant and when clicked
turn black giving a visual clue that they are clickable.