gvle: fix the saving of a new vpz file

to fix the bug, the new package system, where binaries are separated
from sources, has been applied.
(Closes #105)
gvle: fix the "new file" feature

When creating a new file from the file treeview, the Editor did not
initialize the document when it was not a VPZ.
(Closes #109)
gvle: fix the Preferences Dialog

The line with scale widget was not configured, and as soon as a
preference was changed, even a color, the line width was set to 0.
(Closes #108)
gvle: fix header guard fail

ifndef had been made on the wrong macro.
utils: improve download manager

- tests are separated from package
- add the possibility to give the server file path into the url
cli:  fix the remote commands

- args were expected even for the remote command update
utils: fix PackageParser

- if a package depency was declared with eg vle (>=1.1),
an error occured due to the missing patch.
RemoteManager: fix names and urls

- add the missing 'pub' directory into the default remote url of vle.conf
- move local.pkg and remote.pkg into the correspondind pkg dir (eg. pkgs-1.1)
- rename the 'packages' file expected onto a remote with 'packages.pkg'
RemoteManager: rename the mPackages member

- mPackages is renamed mResults since it represents the results of the last
  command
- comments are added
RemoteManager: fix the update action

the remote member was not filled with the results of the command.
cli: fix help for remote manager

- command 'install package' and 'install source' are respectively
'install' and 'source'
RemoteManager: fill the actionSource function

- download of the source is now provided, file is not unzipped
RemoteManager: use tar.bz2 and fill actionInstall

- replace zip archive with tar.bz2 (in order to use Path::decompress) in
  actionSource.
- fill actionInstall, the depenecies are not installed yet
cli and RemoteManager: add user messages

- add management of errors of remote commands
- add user messages to the console for vle cli
RemoteManager: fix actionUpdate results

- the PackageIdUpdate operator is fixed
- the results of the update command is filled with packages with newer versions
- the error is managed by filling mHasError and mMessageError
RemoteManager: fix install

- the more recent version of the package is installed
- one checks if the package is already installed
RemoteManager: update show commands

- add a localshow command, the show command now only show packages from remotes
- the argument of these command is the name of packages
- update help pages
RemoteManager: add messages and log on install

- these logs are for the moment the only way to check if an install failed