Option for treating all content as xml:space='preserve' for XLIFF filter

[Former user]

Original [issue 207](https://code.google.com/p/okapi/issues/detail?id=207) created by @ysavourel on 2012-01-26T17:48:05.000Z:

It would be nice to have an option to force the XLIFF filter to treat all <source> and <target> content has if xml:space='preserve' was set.

Some tools generate output without specifying xml:space and assume it is preserved. Which technically is not wrong since 'default' can preserve. But it's not very inter-operable.

[Former user]

Comment [1.](https://code.google.com/p/okapi/issues/detail?id=207#c1) originally posted by @ysavourel on 2012-01-26T17:51:38.000Z:

[Chase Tingley]

This is a problem we've encountered when dealing with SDLXLIFF and the old Idiom (iws:*) XLIFF that comes out of WorldServer. Both set xml:space='default' and then treat line breaks as significant. A filter-level option would be a decent way to fix this (and we could set it as part of the dedicated sdlxliff config.)

[Chase Tingley]

Fix Issue #207 - Add 'preserveSpaceByDefault' flag to XLIFF filter

When set, the XLIFF filter will preserve XML whitespace by default.

→ <<cset 8b2bc5390ed9>>

[Chase Tingley]

The fix adds the {{preserveSpaceByDefault}} option to the XLIFF filter, which will force the filter to always assume that whitespace should be preserved.