Update POMs - support Windows and production profile

- When passing custom configuration or logs location to Maven,
  use "/" inside property, so we can override it with window's
  path separators "\".

  Any custom value must have ending separator, either "/" for
  Linux or "\" for Windows

  Apply to ${perun.conf}, ${perun.conf.custom} and ${perun.log} properties.

- All found references in pom.xml, app-context.xml and properties files updated
  to respect new scheme.

  When merged, check Jenkins builds if they provide proper value for customized builds.

- Since Maven doesn't respect selected profile in submodules,
  production build can be enforced using "-Dproduction" now.

  Doesn't work: mvn clean install -Pproduction

  Work now: mvn clean install -Dproduction

  ----------------------

  When you specify module to build or trigger build in module folder, then
  you can use "-Pproduction" as always.

  Work: mvn clean install -pl perun-rpc -am -Pproduction

  or in perun-rpc/ folder: mvn clean install -Pproduction