Allow translating default hero names

Also, I moved the newline outside of the "Next Level:" string in Power
tooltips. This is because it messed up po/pot generation.
Merge pull request #910 from dorkster/fixes

Allow translating default hero names
Do not segfault on faulty tile ids, but warn.
Merge pull request #914 from stefanbeller/tileids

Do not segfault on faulty tile ids, but warn.