Make it possible to specify the p4 changes to import through a text file (for debugging) and made various improvements to the branch/merge heuristic detection.
Create lightweight git tags (using the "reset" trick) for the incremental import instead of full-blown ones. Also fix parsing the output of git name-rev for figuring out the last imported p4 change number.
Make specifying the revision ranges more convenient.
Added support for @all as revision range specifier to import all changes to a given depot path.
Also default to an import of #head if no revrange is specified.
Avoid calling fstat for every imported file (slow!) and instead read the file data first into the python process and use the length of the bytes read for the size field of git fast-import.
Changed the import mechanism to write to git fast-import through a pipe instead of having p4-fast-export write to stdout and let the caller connect it to git fast-import.
Speed up the import of individual files from Perforce into git by passing the output of "p4 print" directly to git fast-import. Also try to set the mode of the file in git correctly based on file type heuristics.