no unconditional ASSUME in static routines
check if coefficient ring is field
removed unnecessary and unwanted ASSUME (shadows error msg)
Better doxygen docu. for the introduction
Fixed doxygen descriptions of some files/classes/methods
Merge pull request #594 from surface-smoothers/add.assume.in.primdec.lib

added some precondition checks to 'primdec.lib'
Doxy creates no random directory

NOTE: doxy will clean the output directory now if it already exists
Added the reference about hub (http://hub.github.com)
Make doxygen dig into the new coeff.ring and related #ifdefs (SINGULAR_4_1)
fix some zerogens and size(ideal) issues in primdecint.lib
removed addIdealZ and fixed ASSUME level
updated primdecint_some_special_cases.tst
fix: merhe error: removed addIdealZ
implement tr.622 (lead(I) sets isSB)
removed duplicate tests form ok_s.lst
Removed the timestamp from Doxygen generation mechanismus

NOTE: no cleanup of the target directory...
Exclude system dependent headers: *[cC]onfig.h
Added a link to https://github.com/Singular/Sources/commit/GIT_COMMIT_ID in the doxygen footer
changed test (tr.622)
format
fix: tr.600 (assign to 1x1 bigintmat)