[enhancement] added method to get extensions by case-insensitive URN
[enhancement] added method to get extension field by case-insensitive
field name
[fix] fixed case-insensitive extension searching
Merge pull request #91 from tkrille/BT-22

Bt 22
[fix] fixed typing of text field
[fix] explicitly name column
[fix] Renamed column to reflect code change
Merge pull request #92 from wallner/bt-23

BT-23
extended documentation
Merge remote-tracking branch 'origin/develop' into wibesa