Start Vertica support.
Add initialization, get base tests passing.
Use a single environment variable for Vertica testing.
Stop calling query_params().

dbi_dsn already folds them into the DBI DSN; database URIs no nothing of DBI parameters.
Get Vertica engine working.

All tests pass. Notable things about Vertica:

* There is no support for a string aggregate like MySQL's `group_concat()`.
* There is no support for arrays like in PostgreSQL or Oracle.
* As a result, we have to fetch collections of things as part of a full
  relation, and assemble them into arrays by tracking the change ID. Very SQL
  92; I haven't had to do something like this in a decade!
* Vertica is really picky about data type matching (or maybe ODBC is), so
  we have to cast all values passed as collections of things.
* There is no support for `VALUES()` expressions as tables as in PostgresSQL,
  so we have to use a CTE like we do for Oracle.
* In fact, there is so much different from Postgres that we no longer inherit
  from the pg engine.
* Comments are not supported on table columns, only on projection columns.
  Since we don't know what those are, we don't bother trying.
  http://vertica-forums.com/viewtopic.php?t=144
* No check constraints or `ON (UPDATE|DELETE) CASCADE` support, either.

Still, got it all working reasonably enough.
Separate tag param list from column list.

SQLite and Postgres don't like the "AS foo" syntax in insert param lists,
just in subselect param lists. So separate the two.
I kant spel.

Or remember essential arguments, it seems.
Add sqitch-vertica RPM spec.
Add vertica templates.
All references to Vertica to all docs.

And add a few missing references to Firebird, too.

Also, remove documentation of core `--db-*` options that no longer affect
the `init` command.
Get vertica engine lookup working.

Requires the new `canonical_engine` accessor of URI::db 0.15, so require that
version.
Force Vertica to create default projections.

Otherwise, the first call to `LOCK changes` hangs. So we add an `ENCODING
AUTO` expression to a single column expression in each table. This forces
Vertica to create the default projection at table creation time, as described
in the "Automatic Projection Creation" section of the CREATE TABLE
documentation:
http://my.vertica.com/docs/7.1.x/HTML/index.htm#Authoring/SQLReferenceManual/Statements/CREATETABLE.htm.
Require Config::GitLike 1.11.

Because it uses Moo, not Moose.
Start vertica tutorial.

And remove comments from the Oracle tutorial, a bogus header from the Postgres
tutorial, and the transaction commands from the Vertica verify template. Plus,
add some notes on live-testing Vertica.
Complete the Vertica tutorial.
Note addition of Vertica support.
Fix wayward comment.
Merge branch 'vertica'.