Use Regex for keywords.

Simplify regex code by moving things to the Results class, and by using iterators instead of positions

Delay the construction of controls is SetWindowPanels until the panel is actually shown (initUI). This makes the program start slightly faster.

Package choice fields now reflect in scripts as "/:NO-WARN-DEP:packagename". This suppresses warnings when loading files in that package or using the package as a symbol font.

 - use a single button for install/upgrade
 - show versions of installed package and installer
Named actions in enum PACKAGE_ACT_* to avoid confusion with the status enum.

Used the same mask also for TextStyles.
To keep the text selectable (since the mask is now also used for containsPoint), the future sight cost masks needed to be updated.

New class CachedScriptableMask: like CachedScriptableImage, only containing an AlphaMask instead of an Image/Bitmap.
Use CachedScriptableMask for all masks.

TODO: This introduces some duplicate code in ValueViewers that could be fixed by moving mask to the Style base class.

Added split_text function, which is the 'opposite' of break_text;
Script code "f\n(stuff)" now parses as "f;stuff" instead of a function call, "f(stuff)";
Fixed bug in cursor movement, which caused the closing > of a tag at end of input to be overwritten.

Removing some vestigial "hpt.jpg" files.

Split random_select into random_select and random_select_many.