Implement a first version of a proper build ID computation. ...

Currently, the build ID is built from a few options that are not strictly necessary to be included (build flags and options) - it would be sufficient to just include the build settings introduced by the selected build type (and would reduce the number of build cache folders).

Implement individual building of dependencies.

Let "dflags" specified for build types also be affected by build requirements.

Add suggestion to use --force to rebuild up-to-date targets.

Improve message when the build is skipped on up-to-date targets.

Only call setTarget() on buildsettings that are used to output the final binary. ...

See http://forum.rejectedsoftware.com/groups/rejectedsoftware.dub/thread/626/

Fix appending absolute paths for the working directory.

Fix missing log argument.

Add --force switch for "dub run" and "dub build" and fix --rdmd.

Make sure the target binary gets deleted when the linker has failed.

Add support for a "mainSourceFile" field. ...

The main source file is used as the root to access the whole package. This is important for dependency based building, such as with RDMD and for special build kinds, such as for a future unit test command. This also improves the robustness of "dub build --rdmd".

Main source files are automatically inferred as follows, if not explicitly given:
 1. search first in "source/", followed by "src/"
 2. take the first match of ("app.d", "main.d", "<pkgname>/main.d", "<pkgname>/<pkgname.d>") as the main file for the automatic "application" configuration
 3. take the first match of ("<pkgname>/all.d", "<pkgname>/package.d", "<pkgname>/<pkgname>.d") as the main file for the automatic "library" configuration

Add ".res" to the list of linker file extensions on Windows.

Fix --build=ddox.

The previous OSX fix is also needed for Linux, so change to version(Posix).

Fix "dub run" on OS X. ...

spawnProcess on OS X requires "./" to be appended for starting processes in the CWD.

Don't emit -fPIC for DMD on Windows. Fixes #166.

Add diagnostic message for the target copy operation of the cached build generator.

When doing separate compile/link building, pass (.o/.a/.ao/.dylib/.obj) files to the linker command line. ...

This was already done for .lib files.

Perform target setup when performing a cached build. Fixes #159.

Integrate the rdmd generator into the build generator and start to implement build caching. ...

The basic directory structure, as outlined in https://github.com/rejectedsoftware/dub/wiki/Separate-compilation-and-caching-of-dependencies has been implemented.

Still missing:

 - Dependencies are not built separately
 - The hash part of the build directory is not taking into account any build properties right now

Fix running executables that are not built in the CWD and create the target path if necessary.

Build to a temporary folder only if necessary. Fixes #82.

Fix "dub --build=ddox" and let it open the docs in the system browser automatically.

Remove dub.internal.std.process compatibility code as it doesn't support browse() and the compile status on older DMD versions isn't tracked anyway.

Make "dub build --build=ddox" work for any target type and avoid including dependencies in the documentation. Fixes #142.

Issue -shared and -fPIC when building shared libraries with DMD. Fixes #138.

Make all paths issued by the build generator relative to work around issue #130.

Remove the now redundant GeneratorSettings.compilerBinary field.

Move dub.utils to dub.internal.utils and update copyright dates.

Let the individual compiler classes handle passing arguments to the compiler. Fixes #86.