SQL_C_BLOB was getting #define'd incorrectly if there was not already a definition

SQL_C_BLOB was getting #define'd incorrectly if there was not already a definition
The wxDb::Open() function that takes a wxDbConnectInf() now has a second optional parameter 'failOnDataTypeUnsupported' that defaults to TRUE to maintain current behavior.  This allows users to specify FALSE if they want to try to continue
Reformatting of some text, and removal of old commented out code

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@27227 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775