add makefile for installation and uninstallation

Signed-off-by: Mattias Andrée <maandree@operamail.com>
update readme to reflect addition of makefile

Signed-off-by: Mattias Andrée <maandree@operamail.com>
remove install.sh, use make instead

Signed-off-by: Mattias Andrée <maandree@operamail.com>
fix install instructions: forgot the change directory

Signed-off-by: Mattias Andrée <maandree@operamail.com>
add install instructions using wget instead of git for stable release

Signed-off-by: Mattias Andrée <maandree@operamail.com>
Merge pull request #4 from maandree/master

Add makefile and git-free installation instructions