Change contrib directory to extra

The contrib name (taken from other open-source projects) seems a bit confusing. Extra will probably be clearer.
The Debian data where moved under linux directory, but are also used for ARM. As these are files used to build the package (and not vital to the functionning of duniter)
they have their place in extra.
The Debian data are used by many scripts which were not updated after debian folder move.

release/arch/arm/build-arm.sh

@@ -86,7 +86,7 @@ mkdir -p duniter_release
 cp -R ${SRC}/* duniter_release/
 
 # Creating DEB packaging
-mv duniter_release/release/arch/debian/package duniter-${ARCH}
+mv duniter_release/release/extra/debian/package duniter-${ARCH}
 mkdir -p duniter-${ARCH}/opt/duniter/
 chmod 755 duniter-${ARCH}/DEBIAN/post*
 chmod 755 duniter-${ARCH}/DEBIAN/pre*

release/arch/linux/build-lin.sh

@@ -173,9 +173,9 @@ tar czf "${BIN}/duniter-desktop-${DUNITER_TAG}-linux-x64.tar.gz" * || exit 1
 build_deb_pack() {
 	rm -rf "${RELEASES}/duniter-x64"
 	mkdir "${RELEASES}/duniter-x64" || exit 1
-	cp -r "${ROOT}/release/arch/linux/debian/package/"* "${RELEASES}/duniter-x64" || exit 1
+	cp -r "${ROOT}/release/extra/debian/package/"* "${RELEASES}/duniter-x64" || exit 1
 	if [[ "${1}" == "desktop" ]]; then
-		cp -r "${ROOT}/release/contrib/desktop/"* "${RELEASES}/duniter-x64" || exit 1
+		cp -r "${ROOT}/release/extra/desktop/"* "${RELEASES}/duniter-x64" || exit 1
 	fi
 	mkdir -p "${RELEASES}/duniter-x64/opt/duniter/" || exit 1
 	chmod 755 "${RELEASES}/duniter-x64/DEBIAN/"post* || exit 1

release/new_prerelease.sh

@@ -42,13 +42,13 @@ for asset in $EXPECTED_ASSETS; do
 
     echo "Missing asset: $asset"
 
-    # Debian
+    # Linux
     if [[ $asset == *"linux-x64.deb" ]] || [[ $asset == *"linux-x64.tar.gz" ]]; then
       if [[ $ARCH == "x86_64" ]]; then
-        echo "Starting Debian build..."
-        ./release/scripts/build.sh make deb $TAG
-        DEB_PATH="$PWD/release/arch/debian/$asset"
-        node ./release/scripts/upload-release.js $TOKEN $TAG $DEB_PATH
+        echo "Starting Linux build..."
+        ./release/scripts/build.sh make lin $TAG
+        LIN_PATH="$PWD/release/arch/linux/$asset"
+        node ./release/scripts/upload-release.js $TOKEN $TAG $LIN_PATH
       else
         echo "This computer cannot build this asset, required architecture is 'x86_64'. Skipping."
       fi

release/new_version.sh

@@ -8,7 +8,7 @@ if [[ $1 =~ ^[0-9]+.[0-9]+.[0-9]+((a|b)[0-9]+)?$ ]]; then
   echo "Changing to version: $1"
   # Change the version in package.json and test file
   sed -i "s/version\": .*/version\": \"$1\",/g" package.json
-  sed -i "s/Version: .*/Version: $1/g" release/arch/debian/package/DEBIAN/control
+  sed -i "s/Version: .*/Version: $1/g" release/extra/debian/package/DEBIAN/control
   sed -i "s/version').equal('.*/version').equal('$1');/g" test/integration/branches.js
   sed -i "s/ release: .*/ release: v$1/g" appveyor.yml
 
@@ -21,7 +21,7 @@ if [[ $1 =~ ^[0-9]+.[0-9]+.[0-9]+((a|b)[0-9]+)?$ ]]; then
 
   # Commit
   git reset HEAD
-  git add package.json test/integration/branches.js gui/index.html release/arch/debian/package/DEBIAN/control release/arch/windows/duniter.iss
+  git add package.json test/integration/branches.js gui/index.html release/extra/debian/package/DEBIAN/control release/arch/windows/duniter.iss
   git commit -m "v$1"
   git tag "v$1"
 else