Rollback support for timetz in EF. It didn't work, since the TimeSpan class can't handle time zones, and update and save fails (can't cast interval to timetz).
Merge pull request #336 from Emill/rollback-timetz-support-ef

Rollback support for timetz in EF.
Common.Logging + other logging work

- Killed the internal NpgsqlEventLog, set up Common.Logging instead
- Delocalized logging messages - all logging is in English to help
  analyzing logs provided by users etc.
- Log messages now have level to allow filtering. Existing messages
  categorized as DEBUG or TRACE.
- Removed ultra-high-resolution logging messages to help readability
- Unit tests setup NLog with Common.Logging
Reorganized localization

- Grouped all localized strings into per-language L10N resx files, stored in
  a folder, instead of the previous resx-per-type system
- Code now references localized strings statically rather than via the ResourceManager
- Reminder: localization for logging messages was removed in the previous commit
Merge pull request #334 from roji/logging_redo

Logging and localization makeover
L10N corrections in unit tests
Removed old compatibility versions

We have a mechanism where Npgsql behaves like older versions based on a
connstring param, to help users in cases of breaking changes.

Removed support for the old compatibility versions, but keeping the
connstring param in case we want to introduce breaking changes within
a major version again.
Merge pull request #341 from roji/remove_compat

Removed old compatibility versions
Fix broken compatibility version check
Some work on type mapping loading

- The backend type mapping cache is now a .NET 4.0 ConcurrentDictionary
- Previously the cache was a dictionary that potentially could be read at
  the same time as it was updated (inside the lock). This potential issue
  is gone.
Some changes to hstore testing

- hstore column doesn't get created for all tests, only for
  the hstore one (test speedup)
- If hstore isn't installed at the backend the test is marked as
  inconclusive rather than exception/failure
Fixed up unit test

Hopefully this will fix failing test.
Added execute bit to some EXEs
Use NpgsqlException for backend errors only

- We now throw NpgsqlException only in case of a backend-generated
  issue, as per the DbException/SqlException specs.
- #330
Merge pull request #344 from roji/npgsql_exception

Use NpgsqlException for backend errors only
Updated NpgsqlException docs for clarity
[Ignore] troublesome test

Since commit e87dcc1b1498a2e0303d1b55c434aa1dae678a23 this test fails
on the build server, but not always. Ignoring for now.
Minor work on SSL

- Added IsSecure property to allow the user to know whether we're using
  SSL
- Minor cleanup
Basis SSL test

- #291
Inconclusive tests treated as failures at build server

Some tests can return as inconclusive, e.g. SSL wasn't enabled at the
backend so the test effectively couldn't be run.

We don't want to bother developers who haven't set up Postgresql to
support everything - so inconclusive is very similar to ignore. However,
on the build server we want inconclusive tests to show up as failures,
otherwise we may miss regressions because of misconfiguration.