use ${MKDIR_P} instead of 'mkdir -p'

git-svn-id: https://fricas.svn.sourceforge.net/svnroot/fricas/trunk@1789 b0c55286-4f34-0410-a049-a1e7e93b0762
Remove INDEFINTEGRAL.


git-svn-id: https://fricas.svn.sourceforge.net/svnroot/fricas/trunk@1790 b0c55286-4f34-0410-a049-a1e7e93b0762
Restructure modular evaluation.


git-svn-id: https://fricas.svn.sourceforge.net/svnroot/fricas/trunk@1791 b0c55286-4f34-0410-a049-a1e7e93b0762