Allow install.sh to be run without being the script dir

Author: epheph

cmd/ipfs/dist/install.sh

@@ -3,7 +3,9 @@
 # Installation script for ipfs. It tries to move $bin in one of the
 # directories stored in $binpaths.
 
-bin=ipfs
+INSTALL_DIR=`dirname $0`
+
+bin=$INSTALL_DIR/ipfs
 binpaths="/usr/local/bin /usr/bin"
 
 # This variable contains a nonzero length string in case the script fails