dirstate: eliminate _lastnormal set We can get rid of the _lastnormal set by using the filesystem mtimes to identify the problematic "lastnormal" files on status(), forcing a file content-comparison if the file's mtime timeslot is equal to _lastnormaltime.

test-extdiff: fix 5c0e1222e7c0 temporary dir output

convert/mtn: avoid unnecessary initial test of mtn repo As soon as before() is called, we'll know if there is a problem (and get a better error message).

convert/mtn: add support for using monotone's "automate stdio" when available Currently the convert extension spawns a new mtn process for each operation. For a large repository, this ends up being hundreds of thousands of processes. The following enables usage of monotone's "automate stdio" functionality - documented at: http://www.monotone.ca/docs/Automation.html#index-mtn-automate-stdio-188 The effect is that (after determining that a new enough mtn executable is available) a single long-running mtn process is used for all the operations, using stdin/stdout to send commands and read output. This has a pretty significant effect on the performance of some parts of the conversion process.