[com4]: change variable and function names containg "_" to camelCase

[PaulaSp3]

I changed to most variable and function names to camelCase except a few, for those the "_" suits better IMO, e.g. is_start and calc_zDelta()

[pep8speaks]

Hello @PaulaSp3! Thanks for opening this PR.

• In the file avaframe/com4FlowPy/com4FlowPy.py:

Line 616:13: E265 block comment should start with '# '
Line 615:13: E265 block comment should start with '# '
Line 343:121: E501 line too long (121 > 120 characters)

• In the file avaframe/com4FlowPy/rasterIo.py:

Line 121:5: E722 do not use bare 'except'
Line 112:5: E722 do not use bare 'except'
Line 87:5: E722 do not use bare 'except'

Do see the Hitchhiker's guide to code style