Fix for positioning of glyphs within a bitmap

For positioning of glyphs within a bitmap, roundf(int + float) is used,
where the float is the glyph position and the int is the text position.
When the text position is varied, this may lead to the sum being rounded
in different directions, due to floating point rounding, caused by that
floating point numbers have different precision in different ranges.

This may therefore lead to slightly different positioning for glyphs and
therefore slightly different widths and heights for text strings,
depending on the position they are rendered at.

The solution in this patch is to use int + (int) roundf(float), which
has consistent rounding, and also enables us to use the full range of
ints.

Change-Id: Id1143cdfcbdfa9915ced878ae04df589a3e03cee
Make sure to turn off led after pulse()

setLightLocked() will update mColor. This will cause the led to not be
turned off after the pulse.
When notificationManager starts a attention pulse the led will be kept
on. Since attention is of highest prio nothing can turn it off.
This is fixed by resetting mColor back to 0 after the call.

Change-Id: Id60ef96e5c21b47c23002f0bcf2fae7fb3f2ca10