Display the current MS2 version in the UI

[Gnafu]

Users have no way to tell what version of MapStore2 they are using.
Having a version displayed somewhere in the UI (even if hidden under menus, windows, tabs, or anything) is usefull when reporting a bug.

[offtherailz]

See this as an example:
https://github.com/redux-observable/redux-observable/blob/master/scripts/preprepublish.sh

[mbarto]

[Gnafu]

I'll keep just "Version"

[mbarto]

Should work like this:

• you can specify a parameter to maven with the version: (e.g. -Dmapstore2.version=2017.00.04)
• you can also give a parameter to build.sh (e.g. build.sh 2017.00.04
• we can add a BUILD param to jenkins jobs so that this is passed to build.sh during the build

[Gnafu]

The same mechanism will be usefull to pass Google/Bing/MapBox/other API keys