some refactorings

- cosmetic change
- do not use clever_f#reset() to initialize
- add API for debug
add a test for g:clever_f_repeat_last_char_inputs
ignore \x80\xfd` input sequence

This sequence seems to be sent by terminal.
It's workaround for the sequence.
finalize highlights on the search failed
fix highlights on blockwise visual mode and Ex mode
improve tests for highlights
Revert "finalize highlights on the search failed"

This reverts commit 7ef54fa7f06d76d3073d4225cd0eab31cdf6344c.
update s:first_move['v'] properly (fix #18)
remove useless dependency for test
Merge branch 'dev'