Add support for value limits for NumericInput class.
Add two more UI classes

Thanks to Pengoros for allowing me to use his code.
Unify behaviour of UI elements

- only trigger callbacks on value changes from actual user input
- use "Value" as key in the arg table for callbacks
Fix asset IDs for button states
Add support for alternative time formatting and setting overlay opacity to BuffIconDisplay
Big update to configuration options

- add input to set icons per line
- add functionality to set sorting criteria, time format and overlay opacity
- write proper code to handle change of single options in BuffIconWindow
Add utility to hopefully solve the locale dependent number saving
Convert settings to locale independent format before saving

Also save a version field.
Old settings still should load, if they loaded before, that is.
Re-saving caused parser errors on non-English locales,
because numbers saved as "5,0" read as two table fields,
one with implicit key which saved as "1,0", "2,0" etc.
Just a small wrapper class to setup labels Lotro-like.

Thanks again to Pengoros
Add missing labels and update existing ones.
Also tweak positions a bit.
Fix trigger behavior of Slider
Make ComboBox colors more Turbine-like
Convert tabs to spaces
Bump version to 0.3

Change summary:
- support for alternative time formats
- configurable overlay opacity
- configurable number of icons per line
- make configuration save/load independent of client locale