Merge pull request #1 from He-Ro/master

Added an Option for Localisation
Compute the (expected) output file
FIX minor bug concerning invalid keys in *.properties (key Make_format_ should be make_format_)
Add method to check whether a task is main task in its containing group
Allow for notification of IEnvironmental changes
Simplify generation of texmf.cnf by exporting $TEXMFCNF; this also allow for additional TEXMF directory structures
Added russian translation.
Add static list of all languages with hyphenation to TeXMF
I do not expect this list to change anytime in the future!
Simplify language configuration generation
Merge pull request #2 from ASMfreaK/master

With Russian localization
Make string resource bundle a static field of Task
Use a 3-thread executor in TeXMF
Add a new key (generate_lang_config) to strings.properties
Externalize more strings (exception messages)
Use length check instead of String#isEmpty (missing in Android API8)
Prefix resource strings with "state", "desc" to indicate their purposes
Add comments and section strings.properties
Synchronized access to list of task groups
FIX bug: group param can be `null` in `TeXMF.add(task, group)`
Updated german translation
Added a more detailed explanation of how to translate the project, especially with special characters