Support for less/equal/greater version in requires/conflicts, etc

Add less/equal/greater information to razor_property, and update
importers and other code.

Move the rpm importer from import.c to rpm.c to avoid code
duplication, and then rename import.c to yum.c since that's all that's
left.

 CFLAGS = -Wall -g

 LDLIBS = -lexpat -lz -g -lrpm -lcurl

 all : razor test-driver

 razor : razor.o import.o main.o rpm.o util.o

 test-driver : razor.o util.o test-driver.o

 test : test-driver

 	./test-driver test.xml

 clean :

 	rm -f *.o razor