liblo: use MediaDescriptor / clean-up

Change-Id: If70519066081d8e2c8ed24771369d4afef336896
sw: SetupFilterOptions for any Writer derived filter (html, ascii)

Change-Id: I6f0147ea640a7ad767e2c0112b5e18dcb530fa7c
html: "IgnoreImages" Option, which ignores images at export

Change-Id: I7ff6e83fabbc9f58e16b2617207a37e8dd0061d9
liblo: clean-up liblibreoffice.h(xx)

Change-Id: I596fc3afde94e095ecf97c23617158f3d49afcc1
liblo: extend doc_saveAs with filterOptions

Change-Id: I720f2819955b6f26ea7161493cccb07f873f2a51
html: rename IgnoreImages -> SkipImages, initialize to false

Change-Id: I663264adab001bd1916b13c0d7c75f8a693687d4
sw test: add export test macro, remember test name

Added a new export only macro - this can be used to create tests
which import a document (in any format), and export it in a format
that is being tested. The exported document isn't loaded again, but
it must be asserted using xpath. The primary usage of this is to
test the HTML export.

Change-Id: I1ad300f6274a2181f7f29fed3903b99b68f37fd9
sw html: HTML export test - option with or without "skipImages"

Additionally add loading of HTML document and parsing the document
with libxml - to be able to assert with xpath expression.

Change-Id: I7c62082a124c3705626cd76c8a4cdabc16372399