31-chrome.t: more Chrome tests
Travis-CI: install a recent Test::More
31-chrome.t: more tests
Chrome: add POD
Travis-CI: install Env::PS1, required for testing examples/EnvPS1.PS1
Chrome: MAJOR REFACTORING !!!

Huge refactoring for simplification:
- AngelPS1::Chrome::Flags disappears. Flag constants (Reset, Bold...)
  now return AngelPS1::Chrome objects.
- AngelPS1::Chrome::Color objects have now the same layout as
  AngelPS1::Chrome. Inheritance now applies also to the internal
  representation.

This refactoring will also allow to implement ${} overloading.
Chrome: add ${} overloading

Implement ${} overloading. This allows to use Chrome expression easily
in strings:
    say "normal ${ Red+Bold } RED ${ +Reset } normal";
Chrome: simplify operator overloading decl in Chrome::Color
31-chrome.t: more tests (notes actually)
70-examples.t: mark failure of issue #4 as TODO

This failure is hard to diagnose, and in the mean time makes Travis-CI
failures less useful. So the selected failure cases (perl 5.10-5.14) are
marked as TODO.
See https://github.com/dolmen/angel-PS1/issues/4
Chrome: redo overloading in child class only for perl < 5.18
Default prompt: use WorkingDir_Tilde instead of WorkingDir
examples: use WorkingDir_Tilde instead of WorkingDir
README: fix layout of "Basic Usage"

This issue should explain why nobody ever tried angel-PS1...
Rename "build.pl" to "dist"
Add AngelPS1::Plugin::VCS
Default prompt: use VCSInfo instead of GitInfo
Chrome: add new reset constants: ResetFg, ResetBg, ResetFlags
Add examples/Powerline-basic.t

Reproduce a prompt similar to what is provided by Powerline for Bash.
https://github.com/Lokaltog/powerline
Chrome: fix wrong stringification for Reset flag

Fix stringification error when the Reset flag is the only flag given
along with colors.