Synchronize Python 3 to Makefile (#87)

* Build and install Python 3 module with CMake
Use links, make_pycbf.py, and SWIG to generate interfaces from
CBFlib.html.  Compile with SWIG_PYTHON_STRICT_BYTE_CHAR, which causes it
to be multiply defined.

* Make Python 3 tests take paths of in- and output files from command line
This reduces the constraints on the buildsystem and makes it easier to
clean up after tests: tests do not need to run in a subdirectory of the
input data directory.

* Avoid inconsequential output in Python 3 tests
Do not output lines that would have be removed before subsequent
comparisons.

* Add Python 3 tests in CMake
Several tests rely on cbf_standardize_numbers, which in turn needs
fgetln(3).

* Install python3-numpy-dev dependency for GitHub action
While here, also set the maximum number of concurrent CMake processes to
`nproc`.

Author: hattne

.dev/docker/cmake_ctest.dockerfile

@@ -5,7 +5,7 @@ RUN mkdir /app
 COPY ./cbflib /app/cbflib
 
 RUN apt-get update && \
-  apt-get install -y build-essential git cmake default-jdk gfortran m4 swig
+  apt-get install -y build-essential git cmake default-jdk gfortran links m4 python3-dev python3-numpy-dev swig
 
 RUN cd /app/cbflib && \
   cmake . && \

.github/workflows/cmake_ctest.yml

@@ -21,10 +21,11 @@ jobs:
     - name: install extra dependencies
       run: |
         sudo apt-get update
+        sudo apt-get install -y python3-numpy-dev
     - name: build
       run: |
         cmake .
-        cmake --build . --parallel 4
+        cmake --build . --parallel `nproc`
     - name: test
       run: |
-        ctest --parallel 4
+        ctest --parallel `nproc`