Fix debian/bin/tribler security issue.

Use mktemp to put the log in temp directory with some random template
to avoid malicious user to overwrite someone's file by symlinks.

Please see https://bugs.debian.org/760561

Signed-off-by: Ying-Chun Liu (PaulLiu) <paulliu@debian.org>
Merge pull request #831 from grandpaul/fixbinscript

Fix debian/bin/tribler security issue.
Merge pull request #835 from Tribler/next

Merge next back to devel
Merge pull request #854 from Tribler/next

Merge next to devel
Fix debian/copyright format for empty-short-license-in-dep5-copyright

Lintian reports empty-short-license-in-dep5-copyright warnings.
The License field in debian/copyright should not be empty by dep5 standard.
This commit adds the missing empty field.

Signed-off-by: Ying-Chun Liu (PaulLiu) <paulliu@debian.org>
Use system libjs-excanvas

In Debian, there's system-wide libjs-excanvas. This commit makes
tribler to use excanvas.js from system instead of local one.

Signed-off-by: Ying-Chun Liu (PaulLiu) <paulliu@debian.org>
Merge pull request #860 from grandpaul/fix-copyright-format

Fix debian/copyright format for empty-short-license-in-dep5-copyright
Revert libx11-6 back in debian/control Depends.
Merge pull request #861 from grandpaul/use-system-libjs-excanvas

Use system libjs-excanvas
Added destroy message
Destroy circuits on community unload + remove both sides of a relay
Send less destroy messages
Fix
Merge pull request #878 from Tribler/next

Merge next to devel
Merge pull request #904 from Tribler/next

Merge next back to devel
Merge pull request #905 from egbertbouman/destroy

Destroy message
debugs
add TFTP service
change RemoteTorrentHandler to use TFTP
change code that uses download_torrent() of RemoteTorrentHandler