sql_gen.py: plpythonu_error_handler: Always raise PL/Python exceptions as data_exception so they go in the errors table, instead of aborting the iteration

sql_gen.py: plpythonu_error_handler: Fixed bug where not all PL/Python exceptions start with "PL/Python: " (e.g. on PostgreSQL 9.1 on vegbiendev), so the PL/Python prefix must be optional. Refactored to put IF clause for non-PL/Python exception at end for a more logical ordering of the conditions.

Added inputs/CVS/

README.TXT: Datasource setup: Added steps to place the relevant files under version control

README.TXT: Datasource setup: Accepting the test cases: Don't auto-accept the initial tests because there could be bugs in the initial mappings that would be revealed upon inspecting the test output

sql_gen.py: plpythonu_error_handler: Added section comment before handler block, so that it's clear in the (very long) wrapper function definition what the block is doing

input.Makefile: Documentation: import/steps.by_col.sql: Added -s to make to avoid echoing make commands to the log file

README.TXT: Moved Reinstall all datasources at once to Schema changes and renamed it to Reinstall staging tables to reflect that it is only necessary when the staging table format is changed

README.TXT: Datasource setup: Updating vegbiendev: Added step to also install the staging tables on vegbiendev

README.TXT: Datasource setup: Moved Install the staging tables before Map each table's columns because the install can run in the background while you're mapping. It must, however, come after Auto-create the map spreadsheets because it uses the filenames of the created maps to determine which staging tables to create.