Large number of enhancements and fixes

Added:
- download directory to .gitignore
- Added withSources and withJavadoc to build.sbt plus
EclipseKeys.withSource to import sources and javadoc into eclipse with
sbt eclipse command
- Added application specific configuration to application.conf
- Logging to slf4j
- Akka extension to retrieve appliction configuration settings

Changed:
- Moved code that belongs in download library from AkkaDownloader to
ScalaDownloader
- Changed logback.xml to support sourceThread
- Chained actors Merger, Validator and Cleaner by passing the initiating
thread by reference

Fixed:
- The controller variables were getting mixed up. Fixed this by starting
a separate anonymous download actor context to handle download to ensure
all variables are limited to the context of the download being handled

Removed:
- Moved application.conf and logback.xml from src/main/scala/resources
to src/main/resources
Merge branch 'fix-workdir' into development
Added dependency injection through configurtion file

Added:
- Dependency injection entries to application.conf

Changed:
- Cleaner implementation is loaded through dependency injection
- Merger implementation is loaded through dependency injection
- Splitter implementation is loaded through dependency injection
- Settings to handle dependency injection

Fixed:

Removed:
Merge branch 'add-dependency-injection' into development
Fixed passing a function from configuration as parameter

Added:

Changed:

Fixed:
- Fixed error passing a function from configuration to a method as
parameter, by doing an explicit conversion from Any => Any to Long =>
Int

Removed:
Merge branch 'fix-pass-func-as-param' into development
Changed downloading to master worker pattern

Added:
- Variation on the master worker pattern that supports resource groups
and limiting number of concurrent requests per group
- Added compiler arguments to build.sbt

Changed:
- A lot of code cleanup

Fixed:

Removed:
Merge branch 'master-worker-pull' into development
Bumped version number to v0.2.0-SNAPSHOT
Merge branch 'bump-version-number-to-v0.2.0-SNAPSHOT' into development
Merge branch 'development'