Since rump now requires large buffers of random numbers (>= 512 bytes), use the
jitterentropy library instead of the slow timer pseudo random number generation.
Fixes#1393
On ARM in one way or another 'string.h' prototypes will be used. Move
the definitions from rump_fs to the rump library because it is needed
by all rump based servers running on ARM.
Issue #1141.
This patch changes the top-level directory layout as a preparatory
step for improving the tools for managing 3rd-party source codes.
The rationale is described in the issue referenced below.
Issue #1082
