Log Message:
Update to 2.43

Changelog:
2.43: 2013-12-01
     "set canonicalize" is now effective during import stream reads.
     Introduced =O, =M, =F selectors for parentless, merge, and fork commits.
     The "multiline" modifier on edit is replaced by the =L selector.
     Selection-set evaluation now short-circuits predicates and is faster.
     Fixed a buggy test that caused the reader to choke on submodule links.

2.42: 2013-11-21
     Prevented crash when tagifying a mixed-branch commit.
     svn_no_autoignores -> svn_noautoignores
     Ignore single-rev mergeinfos in Subversion, they're cherry-picks.