First stab at using installed package cache
Forgot to pass '...' into file.path
Use 'write_dcf' for consistent formatting
Can't hash the DESCRIPTION file if it's not available
lockfiles now contain corresponding hash; bump format
Make it optional to use the cache
Make sure options are written out before snapshotting/restoring
snapshot hook was not respecting 'auto.snapshot' option
return TRUE so the callback continues to be called
Merge branch 'master' into feature/cache-packages

Conflicts:
	R/hooks.R
	R/restore.R
	R/snapshot.R
	R/utils.R
some more rstudio/manipulate ignoring; populate hash in annotation of pkg desc
Try out junction points on Windows
don't noop on Windows
Add two common 'worflows' supported by packrat
Use cache dir as <dir>/<pkg>/<checksum>; other tweaks
update defaults + doc
Merge branch 'feature/cache-packages' (caching off for now)

Conflicts:
	README.md