added a new function.

Added function:
StringUtils::eraseChars()

Version was upped.
0.0.11
cleaned up the constructors of ParsableString.

replaced:
ParsableString(string str) ->
ParsableString(const string &str);

removed:
ParsableString(const char *str);

Version up:
0.0.12
replaced the prototype of StringUtils::getString().

const char *getString(void) ->
const char *getString(void) const