Factored OS section out from Makefile, input.Makefile into lib/common.Makefile

Makefile, input.Makefile: Use new $(version), which unlike $(date) also includes the svn revision, to version log files, etc. This way, the working copy can be put back to the way it was at the time of a given import (excluding changes to nonversioned files). This also makes it easier to get all the log files for a particular import when different tables' imports started at different times.

Makefile: Added $(root) for use with $(rootRevision)

lib/common.Makefile: Added $(version), to replace $(date) for versioning log files, etc., and helper function $(rootRevision)

lib/common.Makefile: Added $(revision)

input.Makefile: Removed no longer used $(SED)

lib/common.Makefile: Added $(sed)

Factored $(date) out from Makefile, input.Makefile into lib/common.Makefile

sql_io.py: put_table(): DuplicateKeyException: Fixed bug where indexes with conditions needed to have the input rows filtered by the condition, to prevent trying to retrieve an existing/inserted row using a join on the index columns when the index in fact does not apply. This fixes a bug in the import of taxonconcept where the taxonconcept_0_unique_identifying_name unique index has a condition which was not satisfied for input rows with no identifyingtaxonomicname, causing any input row with NULL in this column to match all taxonconcepts with a NULL identifyingtaxonomicname. This uses ignore_cond()'s new support for constraints that did not fail at least once.

sql_io.py: put_table(): ignore_cond(): Added support for constraints that did not fail at least once, and therefore should not be required to simplify to a non-false value. As part of this, only track the failed constraint in the errors table if it actually failed at least once based on the deleted row count or the `failed` param.