Started the refactoring process
finishes _remove_constraint -> _remove_constraints and _remove_variable -> _remove_variables refactoring
Sympy expressions are now built dynamically from the underlying GLPK problem
Merge branch 'devel' into no_internal_sympy
Removed old sublime project file
Better number objective handling
sympy expressions from solver problem data structure work for GLPK now
Merge branch 'optimization_expression_from_solver_struct' into devel

Conflicts:
	optlang/glpk_interface.py
Merge branch 'no_internal_sympy' into devel