Added a filewrapper interface for I/O operations
  - createFile
created filewrapper.h
added new functionalities: write & append to file
added read_from_file functionality.
Added structs for buffer and cache
Added buffer,h and cache.h (missed in previous commit)
Merge branch 'dheeraj' into nithin

Conflicts:
	physical/filewrapper.c
Merge branch 'nithin' into dheeraj

Conflicts:
	physical/filewrapper.c
Implemented flush page and read page

TODO: Move 'int to byte array' and vice-versa in separate function
Deleted buffermanager.c
Merge branch 'nithin' into dheeraj

Conflicts:
	physical/filewrapper.c
Partially implemented:
-getNextRec
-findRec

highly unstable
implemented openrel, (need updaterec for checking)
opencats is in halfway
Added header files for helpers.c and getnextrec.c
-Corrected datatype in cache (short to int)
-Completed getNextRec
Merge branch 'dheeraj' into nithin

Conflicts:
	include/error.h
Corrected defs.h
Fixed minor errors in errors.c and helpers.c
Modified helpers.c
Merge branch 'nithin' of https://github.com/nithinvnath/minirel into nithin
- Fixed Readpage and flushpage
- Completed getNextRec and findRec
Openrel -> used fns from helpers.c for byte conversion
defs -> added PATH variable; may need further attention.
opencats -> implemented how cache[0], relcat's cache Entry is loaded. Needs to implement same for attrCat.