Base64 implementation

	- Offers base64_encode() and base64_decode to encode arbitrary
	  data
Timesync: Initial commit

	- Current functionality: Call timesync_init() in main, which
	  gossips current localtime to a random node
	- Upon receiving a timestamp, it is printed
	- Timestamps are base64 encoded for great awesomeness
	- Not sure about all of the includes in timesync.h, we might not
	  need all of them
	- TODO: Actual timesync functionality, i.e. upon receiving
	  a timestamp, adjust own localtime and continue gossiping