Improve build docs (#952)

CMakeLists.txt

@@ -125,6 +125,9 @@ if(N2N_OPTION_USE_PORTMAPPING)
   add_subdirectory(${THIRD_PARTY_DIR}/libnatpmp libnatpmp)
   link_directories(${PROJECT_BINARY_DIR}/libnatpmp)
 
+  # Turns on the generic code for supporting either of the above
+  ADD_DEFINITIONS("-DHAVE_PORT_FORWARDING")
+
   # TODO:
   # - this is the odd one out, is it needed?
   include_directories(${PROJECT_BINARY_DIR}/lib_miniupnpc)

doc/BuildConfig.md

@@ -88,6 +88,9 @@ If the pcap library is available then the `n2n-decode` tool can be compiled.
 One of the two UPnP libraries, this one supports the NATPMP protocol.
 See also the next option.
 
+This option depends on the library being installed - on Debian and Ubuntu,
+this is `apt-get install libnatpmp-dev`
+
 ### `--enable-miniupnp`
 
 Enables the other kind of UPnP port mapping protocol.
@@ -95,6 +98,11 @@ Enables the other kind of UPnP port mapping protocol.
 Turning on either of these two UPnP libraries will enable UPnP support within
 the edge.
 
+Both the natpmp and miniupnp depend on the pthread library being enabled.
+
+This option depends on the library being installed - on Debian and Ubuntu,
+this is `apt-get install libminiupnpc-dev`
+
 ### Disable Multicast Local Peer Detection
 
 For better local peer detection, the edges try to detect local peers by sending REGISTER

scripts/cmake_all.sh

@@ -31,7 +31,7 @@ cd build
 # written in such a horrible language.  Since it would be silly to rewrite
 # a one-page wrapper script in python, we submit that this check is wrong.
 # shellcheck disable=SC2086
-cmake $OPTS ..
+cmake .. $OPTS
 
 cmake --build . --config Release