The IDE include checker got to the point where it is actually useful and
this removes a lot of unneeded includes.
Naturally, especially for headers like util.h, this may mean we need to
re-add includes in consuming cpp files that bloats the diff a bit.
Our database uses memmapping and each blk file allocates a file-
descriptor (FD). As such we should increase the number at the start of
the app, if we can.
Notice that the 2000 is chosen to work with a full node that still uses
tiny blk files (128 typically) instead of 1GB files as the Hub makes by
default.
Also fix a bug in the handing code. Using the hardcoded default
FD_SETSIZE made no sense there..
This follows the coding style guideline that the file that contains a
class should follow the exact name of this (main) class.
key.{h|cpp} -> PrivateKey.{h|cpp}
These are technically static libs, but not in any way shared libs.
They are used solely only by this repo and really only by the hub.
Most important, no header files are installed and basically none of
the normal rules for reusable libraries are applied to these files.
tomFlowee