Backport the CMAKE related changesets from the main branch

[e20fecd1945f] Add check target for CMake (#388)
[e74b5db4f2c6] Put the output of chg-len.py in the version string (#389)
[7d166b8b8018] Safer call of ./scripts/chg-len.py on Windows (#389)
[659ba4805a48] Make CMAKE config more consistent with configure.ac (#390)
[63e4468c680e] Add 'Maintainer' CMAKE build type (#388, #390)
[a725503acfe9] Allow CPACK configuration on all platforms
[10242c611190] Create and install lemon.pc (#393)
[48e29534cf03] The deafult target doesn't build lp_test and mip_test (#388)
[0fbbdd578c06] Full path for DoxygenLayout.xml in Doxyfile.in (#395)
[481496e6d71f] SOURCE_BROWSER Doxygen switch is configurable from CMAKE (#395)
[09282720100b] update-external-tags CMAKE target (#395)

 syntax: glob

 *.obj

 *.orig

 *.rej

 *~

 *.o

 *.log

 *.lo

 *.tar.*

 *.bak

 Makefile.in

 aclocal.m4

 config.h.in

 configure

 Makefile

 config.h

 config.log

 config.status

 libtool

 stamp-h1

 lemon/lemon.pc

 lemon/libemon.la

 lemon/stamp-h2

 doc/Doxyfile

 cmake/version.cmake

 .dirstamp

 .libs/*

 .deps/*

 demo/*.eps

 m4/libtool.m4

 m4/ltoptions.m4

 m4/ltsugar.m4

 m4/ltversion.m4

 m4/lt~obsolete.m4

 syntax: regexp

 (.*/)?\#[^/]*\#$

 (.*/)?\.\#[^/]*$

 ^doc/html/.*

 ^doc/.*\.tag

 ^autom4te.cache/.*

 ^build-aux/.*

 ^.*objs.*/.*

 ^test/[a-z_]*$

 ^tools/[a-z-_]*$

 ^demo/.*_demo$

 ^.*build.*/.*

 ^doc/gen-images/.*

 CMakeFiles

 DartTestfile.txt

 cmake_install.cmake

 CMakeCache.txt