Add Czech language characters

[a1346054]

Please check code for code style and other problems. I did not compile it to see if it runs.

[rom1v]

Thank you. The code seems correct, but in practice it does not work on my devices.

Maybe the only supported combinations are those described here (the ones already implemented):

The system recognizes the following Unicode characters as combining diacritical dead key characters:

• '\u0300': Grave accent.
• '\u0301': Acute accent.
• '\u0302': Circumflex accent.
• '\u0303': Tilde accent.
• '\u0308': Umlaut accent.

[a1346054]

I don't know what to say :( Sounds wrong that android does not properly support other keyboard languages than english :(

[rom1v]

Since finally it does not work, I'm closing.