Adds Appendable support, uses StringBuilder instead of StringBuffer #120
Ensure time-zone offset print methods have same code

Testing revealed no difference in behaviour
Fixes #122
Merge branch 'add_appendable_string_builder_support' of https://github.com/CodingFabian/joda-time into CodingFabian-add_appendable_string_builder_support
Support Appendable throughout printing

Ensure that Appendable can be used efficiently in printing
Fixes #120
Fixes #121
Fixes #122
Bump clirr comparison version