Fix the new_crashes generator for HBase so it doesn't close the connection too early.

Also, don't close the connection when requested for the persistent HBase
connection (and only close it when the context is closed).
Merge pull request #1114 from rhelmer/bug847735-silence-modulelist-job

bug 847735 - silence modulelist job in non-error cases
Add a force_reconnect method to connection_contexts.

This allows us to reestablish persistent connections that may die.

Also add unit tests for the persistent HBase context.
Merge pull request #1113 from rfw/hbase_fix_new_crashes

Persistence on disconnect for HBase and fixed new_crashes generator
Skip processing slots only if the slot is newer and the date is newer.
Merge pull request #1117 from rfw/fix_fs_slot_processing

Skip processing slots only if the slot is newer and the date is newer.
Fix a typo in in new_crashes.
Merge pull request #1118 from rfw/fix_typo_in_hbase

Fix a typo in in new_crashes.
Rename variables to be less confusing in hb.crashstorage.
Merge pull request #1119 from rfw/fix_typo_in_hbase

Rename variables to be less confusing in hb.crashstorage.
Stringify dates in the processed_crash dict instead of default.

HBase needs the dates in string form in other places as well, so it not
only affects the JSON dumps but also the timestamps in HBase column
mutations.
Merge pull request #1120 from rfw/stringify_dates_hbase

Stringify dates in the processed_crash dict instead of default.
Ignore non-exsitent date trees when scanning for new crashes.
Ignore non-existent date trees when scanning for new crashes.
Bug 805323 - Double-decode slashes in reasons parameter in search.
Merge pull request #1122 from rfw/empty_date_dirs

Don't throw an exception when we find a missing date dir.
Merge pull request #1123 from AdrianGaudebert/805323-allow-slashes-in-reasons

Bug 805323 - Double-decode slashes in reasons parameter in middleware.
Fixes bug 848806 - Rewrite parameters before assigning default values in search.
Merge pull request #1116 from AdrianGaudebert/848806-middleware-search-date-params

Fixes bug 848806 - Rewrite parameters before assigning default values in...
Add support in the legacy filesystem module for old webhead slot layout.