[geary] Update configure script for compatibility with current unstable jhbuild.

[Michael Gratton <mjog src gnome org>]

commit 8c4c1aefa991b249985399cb2cf55da959314590
Author: Michael James Gratton <mike vee net>
Date:   Thu Feb 2 15:16:45 2017 +1100

    Update configure script for compatibility with current unstable jhbuild.

 configure |   27 +++++++++++++++++++--------
 1 files changed, 19 insertions(+), 8 deletions(-)
---
diff --git a/configure b/configure
old mode 100755
new mode 100644
index b802baf..40c958b
--- a/configure
+++ b/configure
@@ -71,17 +71,28 @@ do
         -h | --help)        configure_help
                             exit 0
                             ;;
-        
-        --prefix)           [ ! $value ] && abort $1
+
+        --prefix)           if [ -z "$value"]; then
+                                # handle jhbuild's use of "--prefix /path"
+                                value="$2"
+                                shift
+                            fi
+                            [ ! "$value" ] && abort $1
                             CMDLINE="${CMDLINE} -DCMAKE_INSTALL_PREFIX=${value}"
                             ;;
-        
-# ignored for autotools compatibility
-        --bindir | --libdir | --sbindir |--datadir | --localstatedir | --includedir) ;;
-        --infodir | --sysconfdir |  --mandir | --libexecdir) ;;
+
+        # ignored for autotools compatibility
+        --bindir | --libdir | --sbindir | --datadir | --localstatedir | \
+        --includedir | --infodir | --sysconfdir |  --mandir | --libexecdir)
+                            if [ -z "$value"]; then
+                                # handle jhbuild's use of "--option /path"
+                                value="$2"
+                                shift
+                            fi
+                            ;;
         --build | --host | --target) ;;
-        --disable-silent-rules | --disable-static ) ;;
-        
+        --disable-gtk-doc | --disable-silent-rules | --disable-static ) ;;
+
         --debug)
                             CMDLINE="${CMDLINE} -DCMAKE_BUILD_TYPE=Debug"
                             ;;