Test \r\n in WhitespaceControlTest.java

[ilg-ul]

Although with the current version that always removes all whitespaces it might not be a problem, for correctness, I think it would be better to also test Windows specific cases too.

This means doubling all tests that use \n with similar ones using \r\n.

In my fork that removes only one line terminator, the test file looks like this:

• https://github.com/gnu-mcu-eclipse/Liqp/blob/ilg-whitespaces/src/test/java/liqp/tags/WhitespaceControlTest.java

The adjusted parser that passes these tests is:

• https://github.com/gnu-mcu-eclipse/Liqp/blob/ilg-whitespaces/src/main/antlr3/liqp/parser/Liquid.g

[bkiers]

With the rewrite of the grammar (from v3 to v4), the Windows \r\n pass out of the box. Unit tests are added in #81