Create MO parser

Refactored a bit too, so we can use interfaces to take Mo and Po files

added fixtures

found that the parser for Po files have a bug... but it works... so not touched

fixtures/fr/LC_MESSAGES/default.po

@@ -0,0 +1,77 @@
+msgid ""
+msgstr ""
+"Plural-Forms: nplurals=2; plural=(n > 1);\n"
+"Project-Id-Version: \n"
+"POT-Creation-Date: \n"
+"PO-Revision-Date: \n"
+"Last-Translator: Josef Fröhle <froehle@b1-systems.de>\n"
+"Language-Team: \n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"Language: fr\n"
+"X-Generator: Poedit 2.0.6\n"
+"X-Poedit-SourceCharset: UTF-8\n"
+
+# Initial comment
+# Headers below
+msgid "language"
+msgstr "fr"
+
+# Some comment
+msgid "My text"
+msgstr "Translated text"
+
+# More comments
+msgid "Another string"
+msgstr ""
+
+# Multi-line msgid
+msgid ""
+"multi\n"
+"line\n"
+"id"
+msgstr "id with multiline content"
+
+# Multi-line msgid_plural
+msgid ""
+"multi\n"
+"line\n"
+"plural\n"
+"id"
+msgstr "plural id with multiline content"
+
+# Multi-line string
+msgid "Multi-line"
+msgstr ""
+"Multi \n"
+"line"
+
+msgid "One with var: %s"
+msgid_plural "Several with vars: %s"
+msgstr[0] "This one is the singular: %s"
+msgstr[1] "This one is the plural: %s"
+
+msgctxt "Ctx"
+msgid "One with var: %s"
+msgid_plural "Several with vars: %s"
+msgstr[0] "This one is the singular in a Ctx context: %s"
+msgstr[1] "This one is the plural in a Ctx context: %s"
+
+msgid "Some random"
+msgstr "Some random translation"
+
+msgctxt "Ctx"
+msgid "Some random in a context"
+msgstr "Some random translation in a context"
+
+msgid "Empty translation"
+msgstr ""
+
+msgid "Empty plural form singular"
+msgid_plural "Empty plural form"
+msgstr[0] "Singular translated"
+msgstr[1] ""
+
+msgid "More"
+msgstr "More translation"