Add github user/repo to session_info()'s output
Recognize Bioconductor packages in session_info()

These packages _must_ have a 'biocViews' field in
DESCRIPTION, according to the How-to at
http://www.bioconductor.org/developers/how-to/biocViews/
Merge pull request #555 from gaborcsardi/fix/session-bioc

Recognize Bioconductor packages in session_info()
Merge pull request #554 from gaborcsardi/fix/session-github-repo

Add github user/repo to session_info()'s output
Don't try to export missing objects
Add test for missing exports
Add warning for missing exports
Update NEWS
Use write_dcf in create
Fix thinko. Closes #556
Fix missing export test
Update test to use bitops instead of removed splines package
Also check imports env for exports
Bump version to 1.5.0.9000
Add date to session_info()
Export print method & re-document
Added new check environment var

Via https://github.com/wch/r-source/commit/f49fe2834e7573571351c7784d3bed461d077645
Tease apart metadata creation from installation
Pull source_pkg into own function
Clarify download message