Unified handling of VM arguments and document's encoding

Commit SHA: 342e4bc8533495f1a1a7f8c5ee60925516a52558 allowed users to
pass specific VM arguments to the VM created to execute the worksheet.
However, that commit caused the worksheet file's encoding to be defaulted
to the system's encoding, if the "-Dfile.encoding" vm argument was not
explicitly provided by the user.

That's annoying, as the default encoding should just be the project's
encoding. And that's exactly the behavior implemented in this commit.

This commit also introduces a `VmArguments` class, which is a simple
container for manipulating VM arguments. For sure it could be much more
richer than it is now, but that is out of the scope of this commit.

Fix #138
Merge pull request #139 from dotta/issue/file-encoding-138

Unified handling of VM arguments and document's encoding
Scanner classes no longer need a `colorManager`

Updated codebase to comply with
scala-ide/scala-ide@SHA: 7d846dfdb40a0dd5c5f9ab6376931d1322ef0130
Merge pull request #142 from dotta/issue/scanner-classes-no-longer-use-colorManager

Scanner classes no longer need a `colorManager`
Bumped version to 0.2.1 for next development cycle
Merge pull request #143 from dotta/transient/bump-version-after-0.2.0-release

Transient/bump version after 0.2.0 release
Resolve compiler errors due to code changes in scala-ide master
Merge pull request #148 from sschaef/t-resolve-warnings

Resolve compiler errors due to code changes in scala-ide master
Update JUnit dependency for Eclipse Kepler
Merge pull request #149 from sschaef/update-junit

Update JUnit dependency for Eclipse Kepler
Makes eval test correctly clean up eval engine

If an evaluation has timeout, wait for the effect of the Stop message
Merge pull request #151 from skyluc/issue/test-interferences

Makes eval test correctly clean up eval engine
Updated plugin-profiles version to 1.0.1
Merge pull request #153 from dotta/update-parent-pom

Updated plugin-profiles version to 1.0.1
Added keyboard shortcut to clear evaluation results

New eclipse Action added.

Keyboard shortcut Ctrl+Shift+C now clears evaluation results.

Fix #132.

Also:
* Moved clearResults into DocumentHolder trait, removed DocumentHandler
Merge pull request #155 from dragos/pr-144

Added keyboard shortcut to clear evaluation results
Fixed source compatibility for latest master

Small fix due to Scala IDE PR #516
(https://github.com/scala-ide/scala-ide/pull/516)
Fixed source compatibility with Scala IDE master

Source compatibility with master was broken by this recent commit
scalaide/scalaide@cf73ce8a4c01c97a476f13e6af5f2237895e30dc
Added 'override' keyword where missing
Merge pull request #157 from dotta/compatibility/ide-pr-516

Fixed source compatibility for latest master