Merge branch 'release/I_0.0.2.20_PRERELEASE'
[maven-release-plugin] prepare release mobbl-core-framework-0.0.2.20
[maven-release-plugin] prepare for next development iteration
Update README.md
- allows configuration on whether to erase the cache or not when an exception occurs during fetch of document through web service
Merge pull request #48 from ptommassen/feature/custom_cache_manager

Custom cache managers
Merge pull request #49 from ptommassen/feature/cache-erasure

Allows subclasses of MBWebserviceDataHandler to not erase the cache on error
Merge branch 'release/I_0.0.2.21_PRERELEASE'
[maven-release-plugin] prepare release mobbl-core-framework-0.0.2.21
[maven-release-plugin] prepare for next development iteration
Update README.md