Prevents double escaping of special chars in arrays.xml/<item> tags
fixed problem with nodpi, added drawable unit testing
add "/libs" unit testing, adjusted naming on previous unit tests
added lib support for "/libs" folder.
added more plurals/color unit tests
ResXmlEncoders: replaced findNonPositionedSubstitutions() by more flexible findSubstitutions().

Also rewritten some bits.
Decode "%d %" with formatted="false". It's not necessary for current aapt, but it's more consistent with "%d % ".
Cleaned up the code related to multiple substitutions in xml strings.
Now one non positional substitution and one positional is detected as "multiple non positional".