Configurable parameter for DSL headwords' maximum size.

By default, it is unchanged, still 256.

In those rare cases when users really need more lengthy
headwords, they could adjust the config file,
maxHeadwordSize parameter.
More reliable transfer of focus from the suggestions list back to the translate line.

Fixes some problems when focus is lost, transferred to random other components, like
buttons or tabbars.
Update locale/lt_LT.ts
Merge pull request #160 from embar-/patch-2

Update locale/lt_LT.ts