Clarify submodules in the git readme and improve standard lib finding

CMake/HPHPFindLibs.cmake

@@ -132,11 +132,23 @@ FIND_LIBRARY(ONIG_LIB onig)
 
 FIND_LIBRARY (CAP_LIB cap)
 
-# potentially make it look in a different directory for the google apps
+if (CAP_LIB STREQUAL "CAP_LIB-NOTFOUND")
+  message(FATAL_ERROR "You need to install libcap")
+endif()
+
+# potentially make it look in a different directory for the google tools
 FIND_LIBRARY (BFD_LIB bfd)
 FIND_LIBRARY (BINUTIL_LIB iberty)
 FIND_LIBRARY (DL_LIB dl)
 
+if (BFD_LIB STREQUAL "BFD_LIB-NOTFOUND")
+  message(FATAL_ERROR "You need to install binutils")
+endif()
+
+if (BINUTIL_LIB STREQUAL "BINUTIL_LIB-NOTFOUND")
+  message(FATAL_ERROR "You need to install binutils")
+endif()
+
 
 include_directories(${HPHP_HOME}/src)
 include_directories(${HPHP_HOME}/src/lib/system/gen)

README.md

@@ -43,6 +43,8 @@ To build HipHop use the following
 cd /home/user/dev
 git clone git://github.com/facebook/hiphop-php.git
 cd hiphop-php
+git submodule init
+git submodule update
 export HPHP_HOME=`pwd`
 export HPHP_LIB=`pwd`/bin
 cmake .