Increase the speed of build with dependencies management

[juliencastelneau]

Instead of getting and building all of our dependencies (VTK, DTK, ITK, DCMTK, ...) each time we want to build a package,
we should use a C++ package manager.
Proposal:

• Client: conan
• Server: bintray
  bintray is an open source project. We should create an open source project and not the commercial licence.

1. Get the dependencies locally.
2. Apply patches if needed
3. Build them
4. Publish the binaries on our bintray server
5. At each build, retrieve them with conan before cmake

Benefits

1. Increase speed
2. Allow to change easily the version of our dependencies, and some roll back if needed