Adapt to new SMILES names at PubChem

This may break some code using the old smiles names "PubChem_Canonical"
and "PubChem_Isomeric" instead of the new smiles names "PubChem"
(including isotopic and stereochemical information) and
"PubChem_Connectivity" (only containing connectivity, but still
canonical).

Further changes in this commit:
- A fix to the test target in the makefile
- Use markdown syntax for link to objects from other packages in the
  documentation
- Adapt the tests
- Increase test coverage a bit

1 files changed, 1 insertions, 1 deletions

diff --git a/man/pai.Rd b/man/pai.Rd
index d509af7..279dd24 100644
--- a/man/pai.Rd
+++ b/man/pai.Rd
@@ -4,7 +4,7 @@
 \alias{pai}
 \title{An R6 class for pesticidal active ingredients and associated data}
 \format{
-An \code{\link{R6Class}} generator object
+An \link[R6:R6Class]{R6::R6Class} generator object
 }
 \description{
 This class is derived from \link{chent}. It makes it easy