committer: Avoid // in xpath.

When using // we assume that the package definition's S-expression is a
nesting of proper lists.  This is not guaranteed to be true, because a package
definition may contain alists.  By using an explicit path to the field of
interest we avoid recursion through all child nodes, thus avoiding child nodes
that are more likely to contain improper lists.

* etc/committer.scm.in (change-commit-message): Replace // with a path for the
PACKAGE symbol.

Change-Id: Idefaec9f5c3538484432e15a5865a68fc16e7369

gnu: r-desctools: Update to 0.99.56.

* gnu/packages/statistics.scm (r-desctools): Update to 0.99.56.

Change-Id: I00956252d699c06408818cced7c0d04e409c61c7

gnu: r-fdrtool: Update to 1.2.18.

* gnu/packages/statistics.scm (r-fdrtool): Update to 1.2.18.

Change-Id: I199c8f82b86c1b8cc40f5dffd6c55f1ff4b727e0

gnu: r-rcppeigen: Update to 0.3.4.0.2.

* gnu/packages/statistics.scm (r-rcppeigen): Update to 0.3.4.0.2.

Change-Id: I3f9ddfdeb14da7bd42bd6e46389da2ec11dc9940

gnu: r-minqa: Update to 1.2.8.

* gnu/packages/statistics.scm (r-minqa): Update to 1.2.8.

Change-Id: Ibdf083085acf888be22d807ea77f2b4caf28de44

gnu: r-robust: Update to 0.7-5.

* gnu/packages/statistics.scm (r-robust): Update to 0.7-5.

Change-Id: I14ceb59373e95295b2bb90712258571226f76205

gnu: r-rrcov: Update to 1.7-6.

* gnu/packages/statistics.scm (r-rrcov): Update to 1.7-6.

Change-Id: I21b0a480e840999d554dfce503a1e2e9137ea455

gnu: r-pcapp: Update to 2.0-5.

* gnu/packages/statistics.scm (r-pcapp): Update to 2.0-5.

Change-Id: I4b4ee28b6777e41fc200e8bad748444b7a34f0e8

gnu: r-robustbase: Update to 0.99-4.

* gnu/packages/statistics.scm (r-robustbase): Update to 0.99-4.

Change-Id: I98104ac5700de8e50fcd8dcbcf0745845c809a9e

gnu: r-fastica: Update to 1.2-5.1.

* gnu/packages/statistics.scm (r-fastica): Update to 1.2-5.1.

Change-Id: I379e9cb4f704e4c8187152762d65f034fd42bf5a

gnu: r-rann: Update to 2.6.2.

* gnu/packages/statistics.scm (r-rann): Update to 2.6.2.

Change-Id: I4be5c6a4f63f5bd572d8b35637ee68c65c89a428

gnu: r-sfsmisc: Update to 1.1-19.

* gnu/packages/statistics.scm (r-sfsmisc): Update to 1.1-19.

Change-Id: Ie8c3682f4b0bf2cc98de7753b0cbed82f6303b48

gnu: r-mvtnorm: Update to 1.2-6.

* gnu/packages/statistics.scm (r-mvtnorm): Update to 1.2-6.

Change-Id: I49def37b078afadc47aaba571fd6ee6a2399f09c

gnu: r-rmarkdown: Update to 2.28.

* gnu/packages/statistics.scm (r-rmarkdown): Update to 2.28.

Change-Id: Id76c14ee9db4e49ecafe5fe0f5e45c0212ad1333

gnu: r-digest: Update to 0.6.37.

* gnu/packages/statistics.scm (r-digest): Update to 0.6.37.

Change-Id: I9445786cc703d704c36cf6c56d06cb53f23505cc

gnu: r-paws-common: Update to 0.7.5.

* gnu/packages/cran.scm (r-paws-common): Update to 0.7.5.

Change-Id: I074d17393bd5ec5bf4ecd860ac0ab0f08bfada04

gnu: r-opencpu: Update to 2.2.13.

* gnu/packages/cran.scm (r-opencpu): Update to 2.2.13.

Change-Id: Ia783a7a278852a5bc0136f015624b1c0283a3ac3

gnu: r-webutils: Update to 1.2.1.

* gnu/packages/cran.scm (r-webutils): Update to 1.2.1.

Change-Id: I680a8ecb149289581ef3cf53fab575b5036191b2

gnu: r-intervals: Update to 0.15.5.

* gnu/packages/cran.scm (r-intervals): Update to 0.15.5.

Change-Id: I587ce6595d3d06177a05f7c719996a6977e09aed

gnu: r-maldiquant: Update to 1.22.3.

* gnu/packages/cran.scm (r-maldiquant): Update to 1.22.3.

Change-Id: I4a08996f8df6d0c746636cfbdbe9fcbaf234749d