provide an ability to exclude files/directories from bundles

[r2evans]

Other than specifically src, lib, bundles, and vcs.history, it would be very useful to omit specific files or sub-directories from a bundle.

My first thought was to include extra_flags="--exclude data-raw", but since bundle forces the use of the internal tar (vice the tar executable), the extra_flags= argument is ignored.

Some options:

• Allow the user to override tar=. There are incompatibilities between internal and command-line tar, so this might not be possible, but it would allow the use of extra_flags= if done correctly.

• Add bundle(..., exclude=) where exclude is either a vector of files/dirs to remove completely or patterns to match against all files. This would require changing from files=basename(project) to an actual vector of files/dirs to include, appropriately filtered.

[r2evans]

Also, would allowing pattern-exclusion help with the current method of copying all files into a new directory? That seems unnecessary (and inefficient, esp for large projects) if you can control the files passed to tar.

[alexiswl]

This would be fantastic!
My very ugly workaround is chmod u-rwx data; bundle_command.sh; chmod u+rwx data;