Fix HTML/XML abbreviation scopes

Fixes emmetio#184
Fixes Sublime-Instincts/BetterTwig#40

This commit fixes abbreviations being disabled in various template syntaxes
such as Jinja2 or Twig, which use common `text.html meta.template` scope to
enable template related snippets and completions in all sub-syntaxes with
easy/short selectors.

Instead of excluding all meta scopes by `- meta`, only relevant ones are,
which indicate embedded or interpolated templating code or html tags.

`text.html.cfml - meta.tag` is removed as it is coverd by
`text.html - text.html meta.tag`.

Note each negative selector is prefixed with `text.html` to make sure to match
only parts within HTML/XML, even if it is embedded in another source code.
That's required to keep abbreviations working in e.g. `source.astro text.html`.

Emmet.sublime-settings

@@ -53,12 +53,12 @@
 	// List of scope selectors where abbreviation marker should be activated,
 	// e.g. plugin will mark text that user types as abbreviation
 	"abbreviation_scopes": [
-		"(text.html | text.xml) - source - meta - comment",
+		"text.html - text.html meta.tag - text.html meta.embedded - text.html meta.interpolation - text.html comment - text.html source",
+		"text.xml - text.xml meta.tag - text.xml meta.embedded - text.xml meta.interpolation - text.xml comment - text.xml source",
 		"source.sass - meta.property-value - meta.property-name - string - punctuation - comment",
 		"(source.css | source.scss | source.less | source.postcss | source.stylus) & meta.property-list",
 		"(source.css | source.scss | source.less | source.postcss | source.stylus) - meta.property-value - meta.property-name - string - comment",
 		"(source.tsx | source.js | source.jsx) - comment",
-		"text.html.cfml - meta.tag",
 		// Inline CSS
 		"text.html meta.attribute-with-value.style (string.quoted | source.css)"
 	],