MPEG TS reader: remove superfluous memory allocation
build system: require libMatroska v1.4.2

See #1096.
tests: add test case for segfaults/assertions from bug 1089
tests: update test cases for safe memory access changes in libMatroska
update libebml/libmatroska to the latest official commits
tests: add tests for sample files from bug 1096

Together with the changes in libEBML and libMatroska this is the last
commit related to #1096; therefore: fixes #1096.