resource: Add smart cropping

This commit `smart` as a new and default anchor in `Fill`.

So:

```html
{{ $image.Fill "200x200" }}
```

Is, with default configuration, the same as:

```html
{{ $image.Fill "200x200" "smart" }}
```

You can change this default in your `config.toml`:

```toml
[imaging]
[imaging]
resampleFilter = "box"

quality = 68

anchor = "Smart"
```

Fixes #4375

1 files changed, 7 insertions, 1 deletions

diff --git a/Gopkg.toml b/Gopkg.toml
index b07a41f7c..9c872585a 100644
--- a/Gopkg.toml
+++ b/Gopkg.toml
@@ -15,7 +15,7 @@
 [[constraint]]
   branch = "master"
   name = "github.com/bep/gitmap"
-
+  
 [[constraint]]
  name = "github.com/chaseadamsio/goorgeous"
  version = "^1.1.0"
@@ -135,3 +135,9 @@
 [[constraint]]
   name = "github.com/gobwas/glob"
   version = "0.2.2"
+
+
+[[constraint]]
+  name = "github.com/muesli/smartcrop"
+  branch = "master"
+