Bug 1264129 - Add verbosity for the shell and autoconf checks in moz.…

…configure. r=gps

Also get an absolute path for the shell.

build/moz.configure/init.configure

@@ -338,14 +338,15 @@ option(env='MOZILLABUILD', nargs=1,
 # It feels dirty replicating this from python/mozbuild/mozbuild/mozconfig.py,
 # but the end goal being that the configure script would go away...
 @depends('MOZILLABUILD')
+@checking('for a shell')
 @imports('sys')
 def shell(mozillabuild):
     shell = 'sh'
     if mozillabuild:
         shell = mozillabuild[0] + '/msys/bin/sh'
     if sys.platform == 'win32':
         shell = shell + '.exe'
-    return shell
+    return find_program(shell)
 
 
 # Host and target systems

build/moz.configure/old.configure

@@ -14,6 +14,7 @@ def encoded_open(path, mode):
 option(env='AUTOCONF', nargs=1, help='Path to autoconf 2.13')
 
 @depends(mozconfig, 'AUTOCONF')
+@checking('for autoconf')
 @imports('re')
 def autoconf(mozconfig, autoconf):
     mozconfig_autoconf = None