Fix packaging version parsing

Comments added to Cargo.toml caused faulty parsing of the version
number by package/cargo_version.sh. Adding the -w switch to grep
fixes this by matching on the whole word 'version' and not matching
on words such as 'Bumpversion'.

package/cargo_version.sh

@@ -1,4 +1,4 @@
 #!/bin/bash
 
 INPUTFILE=$1
-cat $1 | grep version | head -n 1 | cut -d\" -f 2
+cat $1 | grep -w version | head -n 1 | cut -d\" -f 2