AC-1754 ERXExistsQualifier was doing a global replace of the key in the select statement but should have only replaced once. Without this fix, we cannot reliably chain ExistsQualifiers.

Signed-off-by: Aaron Rosenzweig <aaron@chatnbike.com>

Conflicts:
	Frameworks/Core/ERExtensions/Sources/er/extensions/eof/qualifiers/ERXExistsQualifier.java
Modified table alias matching code to avoid incorrect matches when Postgressql. When trying able alias declarations for t4 and t8, it would also match variable bindings for that had a datatype of int4 and int8 e.g., “?::int8” and “?::int4”
Merge branch 'master' of github.com:wocommunity/wonder into ERXExistsQualifier_ReplaceOnce

Conflicts:
	Frameworks/Core/ERExtensions/Sources/er/extensions/eof/qualifiers/ERXExistsQualifier.java
Merge pull request #541 from amagavi/ERXExistsQualifier_ReplaceOnce

looks great after WOWODC presentation, and quick check