Code refactorings
Documentation changes

Removed comments regarding design decisions. MicroViewSlider:draw()
retested to ensure refactoring did not introduce regressions.
removed unneeded comments
Code cleanups for previous refactoring
Indentation fixes
Corrected indentation
Indentation fixes
Fix compiler warning: signed/unsigned comparison
Add destructor for MicroViewWidget base class
Destructor added to prevent compiler warning for object delete.
Improved drawing of gauge minor ticks
Don't bother drawing gauge minor ticks over major ticks
Widget numeric value supression option
The user can add a flag to the style, for all widgets, to supress
the display of the numeric value.

Added new widget method drawNumValue() to simplify the code,
which can also be called by the user, e.g. for a custom numeric
value location.
Code refactoring for widget pointers
Added private methods to replace duplicated code
Merge pull request #18 from MLXXXp/widget_no_value

Add an option to supress the display of the numeric value for widgets