New citation macros

[GeoBosh]

I added some citation macros. As insertRef, they all work in both Rd and roxygen2 documentation.The help page of insert_ref gives some information and examples. Some features are under development.

Feedback and comments will be highly valuable.

Here is the entry from the NEWS file:

• new Rd macros for citations, see below.

• new Rd macro \insertCite inserts citation(s) for one or more keys and records the keys for \insertAllCited (see below).

• new Rd macro\insertCiteOnly is similar to \insertCite but does not record the keys.

• \insertNoCite records the keys but does not produce a citation.

• \insertAllCited prints a bibliography including all references recorded by \insertAllCited and \insertNoCite.

[GeoBosh]

The syntax of the citation entries is now settled, see README, the vignette, or the documentation of insert_ref.

[GeoBosh]

I have now checked the reverse dependencies on CRAN and (some of) Bioconductor, with no problems. If you want to use the new macros, it is a good idea to require v. 0.7 in imports, e.g. Rdpack )>= 0.7).