revise configuration handling

[johntruckenbrodt]

This is a long due revision of the configuration handling. Now, pyroSAR's configuration integrates much better with that of SNAP and a user can directly modify SNAP configuration via pyroSAR.
All changes in a nutshell:

• renamed _dev_config.py to config.py
• centralized variable __LOCAL__ (in drivers.py and config.py) into config.py
• config.py: removed class Storage and its uses
• new class examine.SnapProperties for reading and modifying SNAP configuration
• class examine.ExamineSnap:
  • remove auxdata from identifiers and don't set it as attribute
  • remove config section OUTPUT
  • do not set attributes auxdatapath, properties
  • remove method __update_snap_properties and instead use new SnapProperties class to set attribute snap_properties
  • add new modifiable properties auxdatapath and userpath

Example to modify the SNAP user directory to change the location where SNAP stores any data during processing:

from pyroSAR.examine import ExamineSnap
config = ExamineSnap()
config.userpath = '/path/to/snap/data'

This will add an entry snap.userdir = /path/to/snap/data in $HOME/.snap/etc/snap.properties, which will then be read by SNAP and relevant pyroSAR functions like e.g. auxdata.dem_autoload.

[coveralls]

Pull Request Test Coverage Report for Build 9093547722

Details

• 173 of 201 (86.07%) changed or added relevant lines in 5 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage increased (+0.4%) to 52.264%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pyroSAR/config.py	1	2	50.0%
pyroSAR/examine.py	137	164	83.54%

Files with Coverage Reduction	New Missed Lines	%
pyroSAR/examine.py	1	79.33%

Totals
Change from base Build 9079306250:	0.4%
Covered Lines:	3648
Relevant Lines:	6980

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💛 - Coveralls