Streaming: add ipc_write()
ipc_write() bugfixes
ipc_write(): alloc hugechunks if tx hugechunk even if rx tinychunk
ipc_write(): update stream size on tx
Let streaming chunks track start and end, not just used size
Streaming: add ipc_read()
Streaming: update rx history
Add cnd_signal() call to ipc_write()
Merge branch 'master' into streams
ipc_read(): add line mode
ipc_read(): history typos
Merge branch 'master' into streams

Conflicts:
	kernel/ipc.c
Update ipc_write() to use revamped locks
Update ipc_read() to use revamped locks; also bugfixes
Document streaming chunk size heuristics.
Rename IPC condvars
We aren't gonna flush, nope.
Add ipc_flush()
Fix revamped locks for stream functions
Add ipc_purgeStream()