Make PostgreSQL Provider Case Insensitive (closes #725)

[idseefeld]

With this optional configuration you can disable the the case sensitivity of PostgreSQL.
Users have to ensure valid table, column, and alias names (e.g. without SQL keywords, white space, etc.)
You just need to create the NPoco database like so:

var type = new PostgreSQLDatabaseType() { EscapeTableColumAliasNames = true };
var db = new Database(Database.Connection, type);