Introduce reference point resources (ref-point migration 1/5)

[tobous]

[INTERNAL][I] Introduce new resource implementation

Introduces the new reference point based resource implementation. The
implementation is based on the existing implementation that was then
simplified and adjusted to use reference points.

The new implementation is not used anywhere yet.

Marks the old resource implementations as deprecated.

[INTERNAL][I] Adjust VirtualFileConverter to support new resource impls

Adds methods for the new reference point based resource implementations
to VirtualFileConverter.

Marks the old methods as deprecated.

[tobous]

Adjust exists() check to first check whether the reference point the resource is based on exists.

[tobous]

Rebased onto current master. Fixed minor issues due to merging #1005.

[tobous]

Adjusted implementation to require non-empty paths for resources. This was done to avoid issues with empty paths allowing the creation of IFolder handles for the reference point resource. Such resources would behave unexpectedly when certain methods (like getName()) were called and would allow deleting the reference point resource.

[tobous]

Fixed a C&P error: IntellifFolderImplV2 used the given path for creating a folder child resource instead of first appending it to the relative path of the folder.

[tobous]

Rebased onto current master without any interaction.

[saros-infrastructure]

Here is an overview of what got changed by this pull request:

Complexity increasing per file
==============================
- intellij/src/saros/intellij/filesystem/IntellijFolderImplV2.java  9
- intellij/src/saros/intellij/filesystem/IntellijResourceImplV2.java  5
- intellij/src/saros/intellij/filesystem/IntellijReferencePointImpl.java  7
- intellij/src/saros/intellij/filesystem/IntellijFileImplV2.java  8
         

See the complete overview on Codacy