Challenges balancing update!

This update brings some fixes and changes:

• Balancing for Kills and Rounds Challenges:

  Kills:

• 10k --> 5k

• 25k --> 10k

• 50k --> 25k

• 100k --> 50k

• 175k --> 75k

• 250k --> 100k

  Rounds:

• 50 --> 100

• 100 --> 250

• 250 --> 500

• 500 --> 1000

• few optimizations

• Globalkills showing {Global-Kills} instead of number is fixed!