R: rename deprecate.R to make sure it comes at the end
R: make sure all old names are still exported
R: fix a renaming typo
R: avoid explicit init call when loading package

R calls the init function automatically, if it is named
properly. We need this to make roxygen avoid compiling the
package.
R: do not compile the package for building it, towards #721

Need to trick devtools/roxygen and temporarily remove src/
from the package.