More tests run on Travis - enabled MySQL, PostgreSQL, SQLite, Memcache(d)
Fixed docblock

(cherry picked from commit a4d723e14cf4cacfcf7021fd504586304bf5ffe8)
#261: SQLite does not need different tests since 5.3

(cherry picked from commit f77090548677620c5b836ce271a1eb81f29594f3)
#261: Table is cleared completely to prevent Sqlite "PRIMARY KEY must be unique" error

(cherry picked from commit 9cd83155f50c39d41d649aac3eb224bf5370d02d)
#261: SQLite test fixed: testAdapterOptionFetchMode

(cherry picked from commit be28b741cd115679cfc0bb009826db4c69c79897)
#261: SQLite test fixed: testAdapterAlternateStatement

(cherry picked from commit 544f7013f3be9d407bae0d9afcd68736158ae556)
Drop test tables only if exists, to prevent errors on clean database

(cherry picked from commit 56b225fe7cecb954b9166ce179201b3e493b48de)
Define NULL in test seed using Zend_Db_Expr, so it won't get quoted

(cherry picked from commit 5f0dc97504f83e00f2e066f32a570ed69f6f21e3)
Get current locale properly

(cherry picked from commit 39539aa37fda7a15a5412ddcf9bf4f8eea0060b4)
Remove redundant from() causing errors on postgres

(cherry picked from commit a7e2eb010fc60da90e371b8e93243d87dda004f5)
Do empty-PK detection before we try to obtain nextSequenceId, so it works properly also for the values considered empty

(cherry picked from commit 0d79c0e6cf912a63502285073e8cf041a0597282)
Properly remove previously created row with PK 0 to not fail on unique PK constrains

(cherry picked from commit 03cbdca9ad34555b5261518af221cd77ad0c4884)

Conflicts:
	tests/Zend/Db/Table/TestCommon.php
Provide table and PK name to make test compatible with RDBMS using sequences

(cherry picked from commit d452916a43f80a94edfa16da6178e3e1ba79e677)
Merge pull request #320 from mhujer/db-tests

DB tests are enabled for Travis and fixed to be passing