Introduce a new media shape property to handle mime type

Default mime-type for all media objects:
"application/vnd.sun.star.media"
The problem of missing mime-type detection
still exists. For now only glTF model has
a concrete type.

Change-Id: I4dca26c1c47a564579bbed926bffa3aa5eda6c04
Use stored mime type for stream creation

Change-Id: Iecc50f7964fa63ae028e2fb21d022de1f060c7a7
avmediaogl: simplify namespace

Change-Id: I9cc8a865fa6079dbf9295d2ebafdb020dde5e81d
avmediagst: use boost::noncopyable

Change-Id: I40d1b65a1ea6a1f70cb6f0f6aca705115c0db23c
glTF ODF export: use mimetype to decide about file type

Change-Id: Ib1837bdc7468fb19f55a38f6875e026eea8d3b24
SdFiltersTest: reduce code duplication

Change-Id: I95ddae64001015f911494e11fa15373dfaedd6ba
ODP filter test: embedded media and glTF model

Change-Id: I2340fa5a20a5774e5db78940cf7d4dc584f09b82
Fix make file header

Change-Id: If4e65e5ba5146e93572b314f806a617adb811df9