redo some of the transaction code, get conflicts and obsoletes partly working

now uses a bit array of to-be-installed/removed packages and uses that to
avoid needing to do either per-property searches or repeated merges. but it
really needs to have a bit array of properties too probably

checkpoint before starting on simplifying/cleaning up the existing
transaction code

 #ifndef _RAZOR_INTERNAL_H_

 #define _RAZOR_INTERNAL_H_

 #define ALIGN(value, base) (((value) + (base - 1)) & ~((base) - 1))

 /* Utility functions */

 int razor_create_dir(const char *root, const char *path);

 int razor_write(int fd, const void *data, size_t size);

 #endif /* _RAZOR_INTERNAL_H_ */