maintainer: Cleanup .gitignore

Remove obsolete patterns: ESPResSo is no longer built in-place, but
inside build directories, therefore `/*build*/` is enough; autoconf
has been replaced by CMake.

.gitignore

@@ -1,56 +1,7 @@
-# build system
-Makefile.in
-Makefile
-configure
-config.log
-config.status
-src/acconfig.h.in
-src/acconfig.h
-aclocal.m4
-*.m4
-autom4te.cache
-.deps/
-myconfig.h
-myconfig.hpp
-CMakeFiles
-cmake-build*
-compile_commands.json
 *.log
-
 *.*~
-
-# created by configure
-src/myconfig-final.h
-src/stamp-h1
-doc/latexit.sh
-myconfig-sample.h
-testsuite/runtest.sh
-tools/es_mpiexec
-config/ltmain.sh
-src/python/espressomd/code_info.pyx
-
-# object files and executable
-*.o
-*.lo
-src/libEspresso.a
-Espresso
-Espresso.install
-build.eclipse
-src/featuredefs.pyc
-src/acconfig.hpp.in
-
-# Espresso output
-*.end
-*.obs*
-*.chk
 *.h5
 
-# doxygen
-doc/dg/html/
-doc/dg/background_errors.doc
-doc/dg/background_errors.sorted
-doc/dg/background_errors.unsorted
-
 # IDE
 .idea
 .vscode