providers/virtualbox: Support VirtualBox 4.3 [GH-2374]
Update CHANGELOG
v1.3.5
up version for dev
hosts/gentoo: recognize systemd for nfsd startup and
replace "service" command with /etc/init.d/nfs
Fixing so localhost hosts file entry is not lost when updating hostname. Addresses Issue #2383.
Merge pull request #2384 from nmische/ubuntu_hostname_fix

guests/ubuntu: Fixing so localhost hosts file entry is not lost when updating hostname....
Update CHANGELOG
Merge pull request #2382 from timgus/gentoo_systemd

hosts/gentoo: recognize systemd for nfsd startup and replace "service" command with /etc/init.d/nfs
Update CHANGELOG
hosts/gentoo: use subprocess machinery

/cc @timgus
fix nfs mount fail with freebsd.
Sleep to avoid 100% CPU in waiting time of 'vagrant up'
Add --no-parallel to provision
Merge pull request #2401 from txchen/master

core: sleep to avoid 100% CPU in waiting time of 'vagrant up'
Update cHANGELOG
document common validation pattern
Automatically enable symlinks on vboxsf for VirtualBox 4.1 (see #713 and 387692f9c8fa4031050646e2773b3d2d9b2c994e).
Merge pull request #2414 from Schpidi/symlinks_vb41

provider/virtualbox: automatically enable symlinks on vboxsf for VirtualBox 4.1
Update CHANGELOG