cli: Handle failure of cangjie_get_characters() instead of segsegv
Merge pull request #72 from linquize/cli-segv

cli: Handle failure of cangjie_get_characters() instead of segsegv
cangjie: Realign the function declarations
cangjie: Fix the cangjie_new prototype

The function takes an integer.

It doesn't matter that this integer is made by bitwise-OR-ing the
members of an enum, it still is an integer.

Fixes #73
Merge pull request #74 from Cangjians/issue#73

Fix issue #73