Nicer error messages.


git-svn-id: https://fricas.svn.sourceforge.net/svnroot/fricas/trunk@1748 b0c55286-4f34-0410-a049-a1e7e93b0762
Misc cleanups.


git-svn-id: https://fricas.svn.sourceforge.net/svnroot/fricas/trunk@1749 b0c55286-4f34-0410-a049-a1e7e93b0762
De-hunkify a few files.


git-svn-id: https://fricas.svn.sourceforge.net/svnroot/fricas/trunk@1750 b0c55286-4f34-0410-a049-a1e7e93b0762