adding sanity check to devinstall script

documenting the steps as of 'for dummies request'
wondering how people can still be using such junk (writing a batch file is amazing)
closes #215

doc/installing.rst

@@ -118,14 +118,17 @@ script for it. Read the above Linux instructions, follow them, enjoy.
 Installing on Windows
 ---------------------
 
-The Windows installer used to be a "batteries-included" installer,
-installing everything needed to run Bauble.  The current maintainer
-of bauble.classic cannot run Windows applications. If you want to
-run the latest version of bauble on Windows: download and install
-the dependencies and then install Bauble from the source package.
+The current maintainer of bauble.classic has no interest in learning how to
+produce Windows installers, so the Windows installation is here reduced to
+the same installation procedure as on Unix (Linux and MacOSX).
 
-Please report any trouble and help with packaging will be very
-welcome.
+Please report any trouble. Help with packaging will be very welcome, in
+particular by other Windows users.
+
+The steps described here instruct you on how to install Git, Gtk, Python,
+and the python database connectors. With this environment correctly set up,
+the Bauble installation procedure runs as on Linux. The concluding steps are
+again Windows specific.
 
 .. note:: Bauble has been tested with and is known to work on W-XP, W-7 and
    W-8. Although it should work fine on other versions Windows it has not
@@ -142,7 +145,7 @@ welcome.
 .. _Direct link to download PyGTK: http://ftp.gnome.org/pub/GNOME/binaries/win32/pygtk/2.24/pygtk-all-in-one-2.24.2.win32-py2.7.msi
 .. _Direct link to download psycopg2: http://www.stickpeople.com/projects/python/win-psycopg/2.6.1/psycopg2-2.6.1.win32-py2.7-pg9.4.4-release.exe
 
-the installation steps on Windows:
+The installation steps on Windows:
 
 #. download and install ``git`` (comes with a unix-like ``sh`` and includes
    ``vi``) from::
@@ -216,6 +219,11 @@ the installation steps on Windows:
 
     https://raw.githubusercontent.com/Bauble/bauble.classic/master/scripts/devinstall.bat
 
+   right before you hit the enter key to run the script, your screen might
+   look like something like this:
+
+   .. image:: images/screenshots/sys32cmd-1.png
+
    this will pull the ``bauble.classic`` repository on github to your home
    directory, under ``Local\github\Bauble``, checkout the ``bauble-1.0``
    production line, create a virtual environment and install bauble into it.
@@ -226,6 +234,9 @@ the installation steps on Windows:
    this is the last installation step that depends, heavily, on a working
    internet connection.
 
+   the operation can take several minutes to complete, depending on the
+   speed of your internet connection.
+
 #. the last installation step creates the Bauble group and shortcuts in the
    Windows Start Menu, for all users. To do so, you need run a script with
    administrative rights. The script is called ``devinstall-finalize.bat``,

scripts/devinstall.bat

@@ -1,4 +1,29 @@
 @echo off
+ECHO sanity check
+
+SET SHOULD_CANCEL=0
+
+python -c "1" 2>NUL
+IF %ERRORLEVEL% NEQ 0 (
+ ECHO Python not properly installed
+ SET SHOULD_CANCEL=1
+ goto SKIP_GTK_TEST
+)
+python -c "import gtk" 2>NUL
+IF %ERRORLEVEL% NEQ 0 (
+  ECHO PyGtk not properly installed
+  SET SHOULD_CANCEL=1
+)
+:SKIP_GTK_TEST
+git --version 2>NUL >NUL
+IF %ERRORLEVEL% NEQ 0 (
+  ECHO git not properly installed
+  SET SHOULD_CANCEL=1
+)
+
+IF %SHOULD_CANCEL% NEQ 0 exit /b
+ECHO sanity check passed
+
 IF %1.==. GOTO DEFAULTCHOICE
 set CHECKOUT=bauble-%1
 GOTO CONTINUE
@@ -40,12 +65,8 @@ ECHO create the globalizing script
 IF DEFINED PUBLIC (SET AUDESKTOP=%PUBLIC%\Desktop) & (SET AUSTARTMENU=%PROGRAMDATA%\Microsoft\Windows\Start Menu) ELSE (SET AUDESKTOP=%ALLUSERSPROFILE%\Desktop) & (SET AUSTARTMENU=%ALLUSERSPROFILE%\Start Menu)
 (
 echo @echo off
-echo NET SESSION >nul 2>&1
-echo IF %ERRORLEVEL% EQU 0 (
-echo  mkdir "%AUSTARTMENU%\Programs\Bauble"
-echo  copy "%HOMEDRIVE%%HOMEPATH%"\Local\github\Bauble\bauble.classic\scripts\bauble.lnk "%AUSTARTMENU%\Programs\Bauble"
-echo ) else (
-echo )
+echo mkdir "%AUSTARTMENU%\Programs\Bauble"
+echo copy "%HOMEDRIVE%%HOMEPATH%"\Local\github\Bauble\bauble.classic\scripts\bauble.lnk "%AUSTARTMENU%\Programs\Bauble"
 ) > devinstall-finalize.bat
 
 ECHO please run devinstall-finalize.bat as administrator.