Search cleanup, more binder support

[kallanreed]

A little bit of code cleanup on Search app.

• Some settings are persisted
  • Freq range
  • Power threshold
  • Snap and snap value

Clean up the Freq Save view -- buttons aren't needed now with bound TextField and new TextEntry clear support.

TextEntry -- long press select will now delete all the text up to the cursor. This makes it really simple to clear default text and rename files.

Support binding Checkbox.

[gullradriel]

Good to go.
I like the text delete to cursor too :-)