[pitivi] configure: Fix detection of script dir

[Alexandru Băluț <alexbalut src gnome org>]

commit 7af98ca47c2a089938f2765578d2b8ac374ff72e
Author: Alexandru Băluț <alexandru balut gmail com>
Date:   Tue Jul 19 14:48:07 2016 +0200

    configure: Fix detection of script dir
    
    BASH_SOURCE is not available in /bin/sh sometimes.
    
    Reviewed-by: Thibault Saunier <tsaunier gnome org>
    Differential Revision: https://phabricator.freedesktop.org/D1178

 configure |   11 ++++++-----
 1 files changed, 6 insertions(+), 5 deletions(-)
---
diff --git a/configure b/configure
index f2bbce8..750625c 100755
--- a/configure
+++ b/configure
@@ -1,6 +1,6 @@
 #!/bin/sh
 
-DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+DIR=$(cd "$(dirname "$0")" && pwd)
 
 MESON=meson
 command -v $MESON > /dev/null 2>&1
@@ -26,7 +26,7 @@ then
     command -v $NINJA > /dev/null 2>&1
     if [ $? != 0 ]
     then
-      echo "You should install ninja-build to build pitivi: https://ninja-build.org/";
+      echo "You should install ninja-build to build Pitivi: https://ninja-build.org/";
       exit 1
     fi
 fi
@@ -39,12 +39,13 @@ then
 fi
 git submodule update
 
-# install pre-commit hook for doing clean commits
+# Install the pre-commit hook for doing clean commits
 rm -f .git/hooks/pre-commit
 ln -s ../../pre-commit.hook .git/hooks/pre-commit
 echo ""
 which pre-commit > /dev/null
-if [ $? -eq 0  ]; then
+if [ $? -eq 0 ];
+then
   pre-commit install
 else
   echo "Please install pre-commit from http://pre-commit.com/ before proposing patches"
@@ -53,7 +54,7 @@ fi
 
 BUILDDIR=mesonbuild
 rm -Rf $BUILDDIR > /dev/null 2>&1
-mkdir $BUILDDIR/ && cd $BUILDDIR && $MESON ../ $@
+mkdir $BUILDDIR/ && cd $BUILDDIR && $MESON ../ "$@"
 
 cat <<EOF > $DIR/Makefile
 all: