Bootstrap bit_ops sub-project.

algorithms/encryption/bit_ops/(README.md, makefile, src/bit_ops.(c, h))
	-Bootstrap the `bit_ops` subproject of the `des` project.
	-Add boilerplate makefile, source files.
	-Add placeholder README.
Add test module. Add function prototypes.

algorithms/encryption/bit_ops/src/(bit_ops.(c, h), test.c)
	-Add a `test` module, to contain the project's compiled
	executable's main entry point.
	-Add prototypes for all of the `bit_ops` module's necessary
	functions to `bit_ops.c`; some are commented out, to suppress
	compiler warnings.
Define BitOps_getBit()/BitOps_printBits().

algorithms/encryption/bit_ops/src/bit_ops.(c, h)
	-Define `BitOps_getBit()`; use it to define
	`BitOps_printBits()`.
	-Add documentation comments to each.
Redefine BitOps_getBitString() to return a char *.

algorithms/encryption/bit_ops/src/bit_ops.(c, h)
	-Redefine `BitOps_getBitString()` to return a `char *`, instead
	of writing the binary string to `stdout`, for
	testability/greater modularity.
Add tests/helper macros to the test module.

algorithms/encryption/bit_ops/src/test.c
	-Define helper function-like macros `DEF_UNIT_TEST()` and
	`EXEC_UNIT_TEST()`.
	-Define unit-tests for
	`BitOps_getBit()`/`BitOps_getBitString()`.
Add documentation comments to test module.

algorithms/encryption/bit_ops/src/test.c
	-Add documentation comments to macros/functions/file header.

makefile
	-Compile in `libtap`.
Define BitOps_setBit().

algorithms/encryption/bit_ops/src/(bit_ops.h, test.c)
	-Define, document, and test `BitOps_setBit()`.
Define BitOps_rotLeft().

algorithms/encryption/bit_ops/src/bit_ops.(c, h)
	-Define and document `BitOps_rotLeft()`.
Define a unit-test for BitOps_rotLeft().

algorithms/encryption/bit_ops/src/test.c
	-Define a unit-test for `BitOps_rotLeft()`, itself implemented
	in 73fa6e5.
Merge branch 'algorithms/encryption.bit_ops' into algorithms/encryption.des

algorithms/encryption/bit_ops/
	-Implement a lightweight bit-operations library.