l10n 0.15.2

Creates translatable PO-Files, strong orientation to xgettext

###Changes:###

• Changed version-number-generation for yaml-file a35dbcd
• Testing the version... 659d77d
• Forgot that pub.dartlang.org is not able to interpret hrefs in .md files - changed the changelog format f68f56f
• Forgot that pub.dartlang.org is not able to interpret hrefs in .md files - changed the changelog format deea108
• Short documentation for 'how to use' the gradle tasks d76e5c6
• Forgot to write the CL f068808
• Gradle can update the version in pubspec.yaml and can write a CHANGELOG.md e3a5709
• build.gradle added c0d4c60
• JSON-Capabilities for L10N 8e9b363
• README updated dd078a6
• README updated 648494b
• README updated 0e33ee8
• Subtranslations are possible 8fb2868
• PO-File gets initialize with utf-8 per default (not the case with original msginit) a6539ce
• Set constraint for intl de67f74
• Removed dependency_override d9a051a
• README updated cf0d7fd
• Gave up with 'pub global..., added a working solution to README' a27fd93
• pub update takes quite long - searching for the problem 65e6b15
• Playing with sdk 1.6 e37b4fc
• README updated d79d784
• Wrong locale in Application... 73781ea
• 'locale-dir' was not in git 39c80c0
• README (Typo) 5451168
• README again 9bf3e81
• Install added to README 92ae57c
• Install added to README c6513ee
• Install added to README f02b841
• Screenshot b4158fa
• Screenshot 01a0c2d
• Screenshot fb1a8f5
• mini-Sample and README changed e0a6d04
• mini-Sample and README changed 25c7b20
• mini-Sample and README changed d60861f
• Some more tests 55a90cc
• Added some comments... e212f45
• Dart-File creation works b538065
• Test for merge c4e3b6a
• Remove locale from git 6efa4bd
• Tests... ec29f92
• Nice... 8a21605
• Creation of JSON-File works a5c7d9f
• Mit extract-pot gestartet af92982
• Umstellung von variables auf vars 40b585f
• funkt mit const L10 cfedc91
• Tests mit const-Konstruktor c0e2180
• fromJson construktor umgebaut - zum Testen von const-Konstruktor 391ebab
• Initial release 733b7f4