Refactored with many bug fixes

Handles renames of deleted files
Refactored to improve logic of weird history validation/filtering

Handle modify of deleted file

Fixes bug where 2 versions of file in same changelist occurred.

Provide --case.insensitive option for Linux

For running with p4d on Linux the new --case.insensitive flag will write a suitable journal.
run_conversion.sh takes the -insensitive flag and passes trough as well as using -C1 on journal replay.

Allow --parallel.threads to be specified to reduce memory consumption

Revert "Don't remove git files."

This reverts commit 35e2aad1d305f51d74948f8aab6731077a57128f.

Update to handle more branching cases

v0.1.2

Handle branch of a file which has since been deleted

Alpha for testing

Test version - handles less complex branching fairly well
More complex still has some issues.

Alpha for Windows

v0.0.9

Handle rename on a branch of non-edited file. Added debug info.