Fix LookupError for unknown encodings.

Sets the preferred encoding to UTF-8 if python is unable to find a codec
for the value returned by locale.getpreferedencodings() function.
emit a warning (but don't crash!) on unexpected empty tiles
Merge branch 'master' of git://github.com/overviewer/Minecraft-Overviewer
Update contribManager list with recent contrib scripts
Merge PR #960
Update travis configuration to pull correct minecraft JAR

MC_VERSION will need to be adjusted as part of each update
More agressive texture cache

Especially with regard to jarfile loading
Merge PR #967
Merge branch 'master' of git://github.com/overviewer/Minecraft-Overviewer
Add note about distutils bug.
more better fix for HOME being set on windows
Merge pull request #970 from CounterPillow/patch-1

Add note about distutils bug.
Added more explicit example for texture pack downloading
Updated the wording in the texture installing docs to be less confusing
missed the quotation block
updated texture version to 1.6.2
more wording adjustments
fixed --check-terrain with --config
fix maplabel font with latest gm css
Merge branch 'master' of git://github.com/overviewer/Minecraft-Overviewer