DCSS Challenge Generator 0.5.2 Challenges Little update

Changelog:

• Added Lairless challenge to challenge_database.txt
• Banned Felids from getting The Balista challenge
• Banned additionally Felids, Draconians and Octopodes from getting The Invulnerable challenge
• Allowed Berserkers to get The Archmage challenge (annoying Trog sounds !!FUN!!)
• Updated generic challenges' descriptions to be more precise

Since I noticed source code packages includes unnecessary junk files for using programming, I decided to include minimalistic zip with just Python script and 4 required databases and the only changed database since last release.

Enjoy!