DICOM: expand sequence reading to include known sequences

See QA 9184.
SVS: store the PhysicalSizeX and PhysicalSizeY attributes
Add import missing from rebased commit
Exclude one non-sequence tag from sequence parsing
Fix file handle/line ending issues so that tests pass on Windows
doc: Add ant script for sphinx
ant: Add docs-sphinx top-level target
travis: Use ant to build sphinx docs
ant: Add linkcheck target
Merge pull request #1062 from melissalinkert/qa-9184

DICOM: expand sequence reading to include known sequences
Merge pull request #1064 from melissalinkert/rebased/dev_5_0/svs-physicalsize

SVS: store the PhysicalSizeX and PhysicalSizeY attributes (rebased onto dev_5_0)
Merge pull request #1066 from melissalinkert/rebased/dev_5_0/windows-tests

Fix file handle/line ending issues so that tests pass on Windows (rebased onto dev_5_0)
Merge pull request #1069 from rleigh-dundee/ant-docs-dev50

Use ant to build sphinx docs (rebased)