All patching should be in _preprocess_cmd. config_cmd should just run
configure and nothing else before it, otherwise $PATH is broken when it runs.
Also remove redundant settings to configure, _autoconf already sets them.
We leave explicit AR_FLAGS settings because the builtin rule uses ARFLAGS,
and so would leave AR_FLAGS unset otherwise.
To speedup the depends cached builds, remove some some clutter from the package
files. This mainly incldues removing all the shared libraries and .la
linker files. It also gives stronger guarantees that monero only links
the static libs without any external rvalues.
