Fix 'j', 'k' in select mode cannot handle symbol selecting

The original code uses ChoiceFirstAvail() when using 'j', 'k' in select mode.
However, ChoiceFirstAvail() can only handle word and phrase selectin. If
encounting symbol selecting, ChoiceFirstAvail() will fail to setup the
selecting, and lib will crash eventually. See [1].

[1] http://code.google.com/p/chewing/issues/detail?id=472
Rename functions due to typo (keystoke -> keystroke)
Set isSymbol to 0 in SetChoiceInfo

SetChoiceInfo updates the ChoiceInfo for word or phrase, thus it needs to set
isSymbol to 0 to ensure it will not goto symbol choose in the following code.
See [1] for more information.

[1] http://code.google.com/p/chewing/issues/detail?id=472
Fix misplaced words
Dump words in tsi.src to phone.cin
Redirect GetCharXXX to GetPhraseXXX counterpart
Remove single word phrase in tsi.src
Merge word to phrase when generating us_freq.dat, ...
Remove us_freq.dat, ... related code in build system
Remove LoadChar