Fix cli incompatibility with Windows

When checking for the last slash, use DIRECTORY_SEPARATOR to make the script work correctly when executed under Windows.

PS: can be applied to earlier versions
Add _endt to WidgetBase.php to solve a bug in datetime form widget.
New method WidgetBase::endOfTag() for jForm widgets

Refs #169
Merge pull request #167 from kissifrot/patch-1

Fix cli incompatibility with Windows
New classes to parse composer.json and module.xml. WIP
Parser of module.xml is ready
Vagrant files to create a test environment
Bad function jelix_read_ini call in Config Compiler
Fix issue on using no built lib: installer messages
Module.xml parser: support of LIB_VERSION tag + new Framework class
Config compiler is using the new ModuleInfos object now
Config\Compiler is no more a static class
Improvement: support of Composer range comparison in jVersionComparator
Namespacify some classes of the Installer
Namespacify some classes of the installer, part 2
jInstallerEntryPoint and ModuleInstaller own ModuleInfos object
Rework jInstallerEntryPoint and jInstaller

jInstallerEntryPoint now checks dependencies.
Jelix scripts: remove the deprecated 'migrate' command
Module.xml: 'minversion' and 'maxversion' are changed to 'version'

Same syntax in this new attribute as in composer.json
module.xml: 'creator' and 'contributor' elements changed to 'author'