glTF 3D model embedding: Embed all external resources of *.json file

Store them under /Model/<json_file_name_without_extension>/
modeltools: functions for handling 3D models inside avmedia

Change-Id: Ia2bdad6064db372e1c946b6ab02c434545d1ed45
These changes are not needed any more

Moreover these line causes the same Wshadow warning
which was the reason of adding them.

Change-Id: I6b5793b66db26720626b7924d59e9283168f8abe
Avoid Wsahdow warnings related to boost json parser

Problematic variable: separator -> separator_

Change-Id: Ia4e1b1543f61b03e029e1bc4151ec58334e8df57
ODF export of glTF 3D models

Change-Id: Iea06ea7359b859144df338e1e22675e05bf4a2d7
Use "Insert" instead of "Open" in title of 3D Model insertion file dialog

Change-Id: Ibb6a7df3bf25f7006b71deeebd5abb842a628a46
Store glTF related files in a temp folder which URL can be given to the player

media::XPlayer is constructed by media::XManager with
only one URL parameter.

Change-Id: I3693bce5386ea7f75fa7d9f1a7d744f90440d62b
ODF import of glTF 3D models

Change-Id: I42f7bc63c1f75592ab628407b40d40536e58f18c