Add support to mega.nz URLs

[mrl586]

When I trying download mega.nz URL with megadl, it says:
"WARNING: Skipping invalid Mega download link".

Those links are valid, but megadl not recognize them.

ProblemType: Bug
DistroRelease: Ubuntu 15.10
Package: megatools 1.9.95-2
ProcVersionSignature: Ubuntu 4.1.0-3.3-generic 4.1.3
Uname: Linux 4.1.0-3-generic x86_64
ApportVersion: 2.18-0ubuntu5
Architecture: amd64
CurrentDesktop: KDE
Date: Sun Aug 2 21:13:56 2015
InstallationDate: Installed on 2015-08-01 (1 days ago)
InstallationMedia: Kubuntu 15.10 "Wily Werewolf" - Alpha amd64 (20150728.1)
SourcePackage: megatools
UpgradeStatus: No upgrade log present (probably fresh install)

[mrl586 (mrl586)]

It seems that this feature is added to upstream code.
https://github.com/megous/megatools/commit/9da13bba560cf92fefb4be43c33e1c3551486032

[mrl586 (mrl586)]

This bug is fixed in Xenial (megatools 1.9.95-3), but not yet in wily and vivid.