Issue #1968: Clarify grabber mechanics for newly-mapped channels.
Merge pull request #325 from bconway/master

Issue #1968: Doc fix - Clarify grabber mechanics for newly-mapped channels.
Add a channelno url to play a channel by its user assigned number
Merge pull request #324 from BtbN/channelnumber_http

Add a channelno url to play a channel by its user assigned number
support/configure.inc: fix crosscompiling

--cc= can be whatever. there should be no check if generated
binaries can run while crosscompiling.
Power off LNB when idle

Try to reduce power, when no streams are captured from DVB-S/S2 devices.
Fix the adapter_mask handling for linuxdvb
Graceful exit

It's necessary to do serious checks for the memory leaks using
tools like valgrind. This patch tries to implement a graceful
exit for all tvheadend components and free allocated memory.

Also, some memory leaks were fixed.
webif: updated imdb query url
webui: added bandwidth monitor for stream input
htsp channels: ensure HTSP gets channel update messages
linuxdvb: add output of signal status message
debug: added extra debug for deep analysis of packet handling
build: check for qsort_r independent of platform

Rather than check for specific glibc version on PLATFORM_LINUX, check
the existance of qsort_r.

This fixes the following compile error with musl libc:

CC              src/main.o
In file included from src/main.c:39:0:
src/tvheadend.h:608:20: error: missing binary operator before token "("
 #if !__GLIBC_PREREQ(2,8)
                    ^
build: check for gcc version independent of platform

Use the gcc specific __GNUC__ and __GNUC__ minor to determine gcc version
rather than using the GNU libc specific __GNUC_PREREQ.

This fixes the following compile error with musl libc:
src/descrambler/capmt.c:79:18: error: missing binary operator before token "("
 #if __GNUC_PREREQ(4, 3)
                  ^
build: detect wordsize in a portable way

There are no standard that says that __WORDSIZE should be defined or
in what include file. So in case its not defined we fallback to a
POSIX compliant way to determine wordsize.

This fixes build with 64 bit musl libc.

See https://tvheadend.org/issues/1983
build: typecast NGREG to int

Fixes the following error with musl libc:

src/trap.c: In function 'traphandler':
src/trap.c:178:3: error: format '%d' expects argument of type 'int', but argument 4 has type 'long unsigned int' [-Werror=format=]
   snprintf(tmpbuf, sizeof(tmpbuf), "Register dump [%d]: ", NGREG);
      ^
timeshift debug: correct format string
Merge remote-tracking branch 'origin/pr/330'

Fixes #1983
Merge remote-tracking branch 'origin/pr/328'