- to avoid accidental removal

- so it better reflects the content

- do not clutter up ~/

- not sure if there's a need for log file in predefined location
- installer is verbose enough to signal errors

- to avod error when deleting nonexisting buffer

- show installation destination

- batch process just iterates through the lines and calls specified
action
- individual actions give visual feedback aswell
- allow Helptags command as a part of installation process

- merge with view()
- no need for having both

- log is global array so log can be viewed any time
- log gets written to a defined location ~/.vim-vundle/vundle.log
- TODO: write log changes as they happen

Use only already loaded Bundles for installation, do not source vimrc again

BundleInstall sources the current vimrc in order to reload all Bundles
in order to consider new Bundles that might have been added by the user
directly on their vimrc file. This, however, should not be Vundle's
responsibility, changes in vimrc should not be applied unless it is
re-sourced explicitly by the user.

This makes Vundle use the known list of Bundles for installation.

- but don't like it

Marking the installer buffer as not modified

- TODO: refactor: extract common code

Installer buffer is marked as modified after each installation. Mark it
as nomodified so that no warnings are shown when the buffer is closed.