DEP1: Implement SDL package description support

[s-ludwig]

This implements DEP1 with a few fields added that are still absent from the wiki page.

[s-ludwig]

Wiki page is updated now.

[s-ludwig]

Since this is an additive change and all tests pass, I'd just merge this as it is. Does anyone want to have a look first? The actual change set is not as big as it looks. The "sdlang-d" commit can just be ignored for the review.

It would also be interesting to review the SDL based format to see if there is anything that could be optimized in terms of usability (see the DEP link at the top).

[grogancolin]

Just testing it out on my local branch now.
I've rewritten my local dubs dub.json to dub.sdl to see if it can parse it.

name "dub"
description "Package manager for D packages"
license "MIT"
copyright "Copyright © 2012-2014 rejectedsoftware e.K., Copyright © 2012-2014 Matthias Dondorff"
authors {
        "Matthias Dondorff" 
        "Sönke Ludwig"
}
targetPath "bin"

configuration {
            name "application"
            targetType "executable"
            mainSourceFile "source/app.d"
            libs "curl"
            versions "DubUseCurl"
}
configuration {
            name "library"
            targetType "library"
            excludedSourceFiles "source/app.d"
            libs "curl"
            copyFiles-windows "bin/libcurl.dll" "bin/libeay32.dll" "bin/ssleay32.dll"
            versions "DubUseCurl"
}
configuration {
            name "library-nonet"
            targetType "library"
            dependency "vibe-d" version="~>0.7.19-rc.4" optional="true"
            excludedSourceFiles "source/app.d"
}

It fails to parse it, throwing an unhelpful error:

./bin/dub                                                                                                                              
Failed to parse package description for dub  in /home/colin/Projects/dub/.
core.exception.RangeError@source/dub/recipe/sdl.d(170): Range violation

It would be good to add a some debug info here for the user to understand whats going wrong.

Also, this is my first time writing an SDL file, so the above may be wrong!
The above SDL is indeed wrong!

Here is the dub.sdl that will build dub:

name "dub"
description "Package manager for D packages"
license "MIT"
copyright "Copyright © 2012-2014 rejectedsoftware e.K., Copyright © 2012-2014 Matthias Dondorff"
authors {
        "Matthias Dondorff" 
        "Sönke Ludwig"
}
targetPath "bin"

configuration "application" {
            targetType "executable"
            mainSourceFile "source/app.d"
            libs "curl"
            versions "DubUseCurl"
}
configuration "library" {
            targetType "library"
            excludedSourceFiles "source/app.d"
            libs "curl"
            copyFiles-windows "bin/libcurl.dll" "bin/libeay32.dll" "bin/ssleay32.dll"
            versions "DubUseCurl"
}
configuration "library-nonet" {
            targetType "library"
            dependency "vibe-d" version="~>0.7.19-rc.4" optional=true
            excludedSourceFiles "source/app.d"
}

My suggestion though would be to add an error something along the lines of:
Failed parsing at

[s-ludwig]

The error checking code was still missing. Now outputs something along the lines of:

Failed to load package in .../: .../dub.sdl(20): Error: Missing value for 'configuration'.

[grogancolin]

Yeah, it's much better/easier to use when the error checking is in there!

Looks good!

[s-ludwig]

Merging to master. @grogancolin Thanks for the review!