The "--extra-include-dirs" and "--extra-lib-dirs" options end up adding
references to too many unnecessary inputs.  Turns out that these options
aren't even needed for a correct build.

The "--bindir" option is not as useful as it seems as the configured location
is embedded in the outputs.  Instead of using "--bindir" it seems better to
build a statically linked binary and move the binary to its own output to
avoid references between the "out" and "bin" outputs.

* guix/build/haskell-build-system.scm (configure): Do not pass "--bindir",
"--extra-include-dirs", and "--extra-lib-dirs".

* guix/build/haskell-build-system.scm (register): Strip references to the doc
output from the generated package config files; move the haddock files from
the "doc" output to the "lib" output.

* guix/build/haskell-build-system.scm (register): Use lib output if it exists.

* guix/build-system/haskell.scm (lower): Add OUTPUTS keyword and add the
"static" output in the common case.
(haskell-build): Set the default value for the OUTPUTS keyword to include the
"static" output.
* guix/build/haskell-build-system.scm (install): Move static libraries to the
"static" output if it exists.

* guix/build-system/haskell.scm (haskell-build): Add keyword PARALLEL-BUILD?
and pass it on to the builder.
* guix/build/haskell-build-system.scm (build): Accept keyword PARALLEL-BUILD?
and pass the number of parallel jobs to GHC.

* gnu/packages/haskell.scm (ghc-8.8): New variable.

* gnu/packages/virtualization.scm (ganeti-instance-debootstrap)[source]:
Add a file-name field.

* gnu/packages/java.scm (java-guava)[source]: Add a file-name field.

* gnu/packages/geo.scm (osm2pgsql): Update to 1.2.2.

* gnu/packages/geo.scm (libosmium): Update to 2.15.6.

* gnu/packages/geo.scm (gdal): Update to 3.1.2.

* gnu/packages/geo.scm (gdal)[inputs]: Add postgresql.
[native-inputs]: New field. Introduces pkg-config.

* gnu/packages/irc.scm (quassel)[source]: Only remove bundled inxi script.
[arguments]: Adjust 'patch-inxi-reference phase to symlink packaged inxi
to where quassel expects it to be.

This allows compiling the module without the (gnu packages maven) module being
available.

* guix/build-system/maven.scm (%default-maven-plugins): Rename to
default-maven-plugins, and convert to a procedure.
* doc/guix.texi (maven-build-system): Update.

* guix/build-system/maven.scm: New file.
* guix/build/maven-build-system.scm: New file.
* Makefile.am (MODULES): Add them.
* doc/guix.texi (Build Systems): Document the maven build system.

* gnu/packages/maven.scm (maven-jar-plugin): New variable.

* gnu/packages/maven.scm (maven-surefire-plugin): New variable.

* gnu/packages/maven.scm (maven-surefire-common): New variable.
* gnu/packages/java.scm (java-hawtjni, java-jansi-native, java-jansi):
Install from pom file.

* gnu/packages/maven.scm (java-surefire-junit4): New variable.

* gnu/packages/maven.scm (java-surefire-common-junit4): New variable.

* gnu/packages/maven.scm (java-surefire-common-junit3): New variable.

* gnu/packages/maven.scm (java-surefire-common-java5): New variable.

* gnu/packages/maven.scm (java-surefire-extensions-api): New variable.

* gnu/packages/maven.scm (java-surefire-booter): New variable.

* gnu/packages/maven.scm (java-surefire-api): New variable.

* gnu/packages/maven.scm (maven-shared-utils-3.1): New variable.

* gnu/packages/maven.scm (java-surefire-logger-api): New variable.

* gnu/packages/maven.scm (maven-compiler-plugin): New variable.

* gnu/packages/maven.scm (maven-shared-incremental): New variable.

* gnu/packages/java.scm (java-plexus-compiler-manager): New variable.
(java-plexus-compiler-api, java-plexus-compiler-javac): Install from pom
file.
(java-plexus-compiler-javac): Install plexus components file.

* gnu/packages/java.scm (java-plexus-java): New variable.

* gnu/packages/maven.scm (maven-core-bootstrap): Make public and hidden.
(java-plexus-component-metadata): Move to ...
* gnu/packages/java.scm: ... here.

* gnu/packages/java.scm (java-qdox-2-M9): New variable.
(java-qdox): Install from pom file.

* gnu/packages/maven.scm (maven-resources-plugin): New variable.

* gnu/packages/maven.scm (maven-filtering): New variable.
* gnu/packages/java.scm (java-sisu-build-api): Install from pom file.

* gnu/packages/maven.scm (maven-plugin-annotations): Install from pom
file.

* gnu/packages/maven.scm (maven-artifact-transfer): New variable.

* gnu/packages/maven.scm (maven-enforcer-plugin): New variable.

* gnu/packages-maven.scm (maven-enforcer-rules): New variable.