csage: build system (#14726)
csage: gitignore
csage: gmp vs mpir
python-sage fix reference to libsagegap in permgroup.py doctest
Merge branch 'build_system' into csage_build_system
Merge branch 'csage_build_system' into python_sage_build
cliquer: track untracked patches
reduce cliquer patching (#14349)
python-sage: check whether gprc.expect is available (#14749)

(otherwise subsequent tests will timeout)
python-sage SAGE_ETC (#14750)

- gp.py
- qepcad.py
python-sage: move files around, turn into templates

(this is to help git keeping track)
python-sage more explicit import/include paths

intended to work with -I<parent_directory_of_'sage'>
python-sage: comment on header hack
python-sage: build system

- BLAS, BLAS2 check
- generate setup.py, module_list.py
- AC_ARG_VAR
- am_check_python_headers
- AM_DEFAULT_EXT globally (?)
- common makefile
  - dependency tracking for cython files
  - some automake global flags
  - some recursive targets
- add all makefiles to AC_OUTPUT
python-sage: module_list

- BLAS
- conditional extensions
- include paths
- m4ri extra_compile_args
python-sage s/lib(gap|ecm).so/libsage\1.so/

lib(gap|ecm).so already exists and confuses autotools

RECHECK: module_list
python-sage: build system

- header checks
  - cliquer/cl.h
  - flint
  - libgap
- create dependency dummies for cython
- AC_AUTO_HEADER (reduce cruft in gcc-calls)
- checks
  - jinja2
  - whether cython supports dependencies
  - cliquer/cliquer.h
- as_ac_expand
python-sage: Makefiles
python-sage: Makefiles
python-sage gen_interpreters.py