Bug fixes and memory optimizations

• Memory and GC optimizations - contributed by Matt Swift.
• Fixed missing ToolTipText bug with form entities.
• Fixed default size for TextInput with multilines.
• Added min size for panels when auto-adjust height.
• Added support in line up / down when editing multiline text input.
• Added useful getter functions for specific types in form (string, int, float, bool..)
• Added default value to form GetValue() methods.
• Fixed bug with animators not working in panels that have clipping overflow when mouse is outside boundaries.