Show progress of installation

[voxspox]

Installing YCM per Vundle shows a message:
"Processing 'Valloric/YouCompleteMe'"
and it seams that the installation hangs / fails here.

Actually, the repo is very big (>200MB) and this takes some time to download.

Please add a progress indicator for the installation process.

[M4rtinK]

I've just hit the same issue - the VIM UI stops responding and seeming nothing is happening in the background, which could be pretty confusing to users.

Only careful observation of running tasks or the bundle directory reveals a git clone is going on in the background. So some for of progress reporting (even just a log filer for now) would be really appreciated! :)