Fix RPM build script to properly handle release versions.

Tag version 0.9.21.

Fix version inference for the RPM build script. ...

The leading "v" of the tag needs to be dropped.

Update change log.

Merge branch '0.9.21'

Following rubygems version specification for approximate version more closely.

Use the cURL-less configuration for unit testing to avoid linker errors.

Use up to date DUB release.

Add build status badge.

Add a TravisCI recipe.

Fix compilation on 64-bit systems.

Improve wording.

Prepend an explicit .\ when executing executables in relative paths on Windows, too. ...

Sometimes the wrong executable was picked up for "dub run" or "dub test".

Implemented ~>1.3.5 version specifier similar to what rubygems are doing.

Add script for building an RPM package. See #245. ...

Thanks @etcimon for the initial version of the RPM spec file.

Support --combined and --force flags for "dub test". Fixes #247.

Don't downward inherit Have_* versions and only partially string import paths. ...

This change allows library builds to be reused for multiple dependees in most situations. String import paths are now only downwards inherited for packages that already have string import paths defined.

Add the target platform to the .dub/build/* cache folders. ...

Enables sharing of the same package folders for different platforms.

Fix typo.

Add --force-remove switch and reimplement PackageManager.remove. ...

remove() now first checks for untracked files and leaves the package untouched if it finds some and no force_remove is supplied. This means that after the user gets an error concerning untracked files, it's possible to rerun dub with --force-remove to remove the package cleanly.

Warn when using -m32/-m64 directly.

Improve error messages for errors during package removal.

Improve error message in case of missing packages.

Fix unit tests to use lower case package names.

Change Dependency.toString to output "x.y.z" instead of "==x.y.z" for exact versions.

Fix triggering an assertion when storing dependencies in advanced format. ...

The code was assuming that such dependencies had always exact versions, which is of course not always true (it should, however, be true for dependencies with a "path" field).

Print a more descriptive error message when PackageManager.getTemporaryPackage fails.

Fix condition for testing if a package description exists.

Add assertion message.

Don't use "echo off" to avoid influencing potential parent batch files.