remove controversial & undocumented deprecation
Overrides Java launch method to find existing Scala launches

Since Eclipes 3.8, a package private method is used by JavaLaunchShortcut
to find existing launch configurations for a given type.
Overrides the Java launch method to use different logic to find the Scala
launch configuraitons.

Fixes #1001447
Add Apply case to ScalaCompletions. Fixes #1001218

This allows scalaCompletions to handle method invocation completions.
Also refactored scalaCompletions to tidy things a little.
remove unneeded comment
review comments - make stuff options
give correct start point in completion

for calls to methods in scope
remove val in for
Merge pull request #509 from adriaanm/master

Upgrade to scala-maven-plugin 3.1.5, scala-xml 1.0-RC3
Merge pull request #507 from skyluc/issue/new-config-each-run-1001447

Overrides Java launch method to find existing Scala launches
fix midword method completions
Update sbt version after 0.13.0 release
correcting centralization to private-repo.typesafe.com made mandatory by SSL SNAFU
Merge pull request #508 from huitseeker/undocumented-deprecate

remove controversial & undocumented deprecation
Merge pull request #512 from huitseeker/sbt-update

Update sbt version after 0.13.0 release
Tests mail fail with an exception, we need to retry those too.
Uses new debug view selection support

In Eclipse 4.x, a new way to follow the current selection in the debug view was implemented,
as debug specific support.
The old way was slightly broken, and was no more working for selection changes not triggered
by the user. A temporary fix was implemented in Scala 3.0.x, to support Eclipse 3.x and 4.x.
This commit replace the old code and the fix by a solution using the new support.

Fixes #1001585
Need to be backported in 3.0.x-juno.
Merge pull request #511 from skyluc/issue/current-selected-thread-1001585

Uses new debug view selection support
Mark output folders as "Derived".

Derived folders won't appear in "Open Resource", polluting
names with classfiles.

Fixes #1000260 (which regressed at some point in time).
Merge pull request #517 from dragos/issue/flaky-test-errors

Tests may fail with an exception, we need to retry those too.
cleaning up test after implementation of tokenize(str:String, ...)

Along with #521, #523, fixes #1001866