add support for evaluating the correct platform to use in a connection
extract abstract base driver classes for vendors
remove unnecessary parenthesis
fix database version string evaluation for SQL Server
fix wrapping PDO exception properties
add tests for driver abstraction refactoring and automatic platform version detection
move mysqli connection test to new namespace
document automatic platform version detection
add upgrade instructions due to automatic platform version detection
add automatic platform version detection for PostgreSQL 9.1
skip tests for uninstalled extensions
revert PDO exception wrapping tests
throw exception on unexpected Oracle database version string
add doc blocks for abstract methods
simplify database platform retrieval
Merge pull request #487 from deeky666/add-platform-version-switch

Add automatic platform version detection