handle empty string in sort key

bug fix sorting

Now allows export of XML in different encodings
Has install-locally script for use with sumo

Installation changed to use mostly setup.cfg and added a script for local installation.

Another fix to trimming the toplevel group

Fixed issue with triming config from xml in alh_to_xml

Removing the treelib might break some things

improvements to the filter/ForcePV handling to create equivalent Phoebus and ALH configs

fixes to filter/ForcePV

Bug fixing

-i option added and removed print

Bug fixes:
alh_to_xml backwards compatible to py3.5
error instead of crash when parent in alh ist not found
script properly installed
reporting version in alh-to-xml

py3.5 compatible version from git tags (versioneer)

More metadata and no versioneer

Completed integration with BII-Controls:
creates valid phoebus and alh files from the same tree structure.