Fixed small javadoc error.
When Scala version not set in plugin configuration or project properties, check direct dependencies (transitive cannot be checked in "generate-resources" Maven lifecycle phase) looking for "org.scala-lang:scala-library" and use its version, if found.
This improvement was suggested in https://github.com/scoverage/scoverage-maven-plugin/issues/13.
GA configuration added to 'site.xml'.
'scalac-scoverage-plugin' version used upgraded from 1.0.1 to 1.0.2. This fixes https://github.com/scoverage/scalac-scoverage-plugin/issues/74.
'README.md' file - note about minimal scala-maven-plugin version (this was not clear, see https://github.com/scoverage/scoverage-maven-plugin/issues/13), version upgraded from 1.0.1 to 1.0.2 in preparation for 1.0.2 release.