fix: warnings in IntegerProgramming/

quick fix for warnings in IntegerProgramming
(assuming the warnings in the .cc files were unimportant)
chg: fewer univariate factorizations if input is symmetric
fix: compiler warnings due to deprecated conversions
new: pyobject can be converted to newstruct, if defined
fix: don't segfault when assigning non-newstructed custom types to newstructs
chg: shorter error
Merge pull request #139 from YueRen/gfanlib

compiler warnings
fix: bigintmat transpose, add, etc
fix: compiler warning
fix: compiler warnings
new: newstruct_desc can be utilized by non-newstruc custom types
Merge branch 'master' of git://github.com/Singular/Sources
fix: wrong computation of d1
chg: disclosuring fewer of newstruct
Merge pull request #140 from alexanderdreyer/master

Better Interaction between custom blackbox types
fix: newstruct convertible to poly and other ring-dependent commands
Merge pull request #141 from alexanderdreyer/master

Fix: newstruct convertible to poly
Merge pull request #142 from mmklee/factory

Factory
fix: pyobject falls back to newstruct operations
fix: pyobject handles ternary operations acordingly