:sparkles: Implement Page bundling and image handling

This commit is not the smallest in Hugo's history.

Some hightlights include:

* Page bundles (for complete articles, keeping images and content together etc.).
* Bundled images can be processed in as many versions/sizes as you need with the three methods `Resize`, `Fill` and `Fit`.
* Processed images are cached inside `resources/_gen/images` (default) in your project.
* Symbolic links (both files and dirs) are now allowed anywhere inside /content
* A new table based build summary
* The "Total in nn ms" now reports the total including the handling of the files inside /static. So if it now reports more than you're used to, it is just **more real** and probably faster than before (see below).

A site building  benchmark run compared to `v0.31.1` shows that this should be slightly faster and use less memory:

```bash
▶ ./benchSite.sh "TOML,num_langs=.*,num_root_sections=5,num_pages=(500|1000),tags_per_page=5,shortcodes,render"

benchmark                                                                                                         old ns/op     new ns/op     delta
BenchmarkSiteBuilding/TOML,num_langs=1,num_root_sections=5,num_pages=500,tags_per_page=5,shortcodes,render-4      101785785     78067944      -23.30%
BenchmarkSiteBuilding/TOML,num_langs=1,num_root_sections=5,num_pages=1000,tags_per_page=5,shortcodes,render-4     185481057     149159919     -19.58%
BenchmarkSiteBuilding/TOML,num_langs=3,num_root_sections=5,num_pages=500,tags_per_page=5,shortcodes,render-4      103149918     85679409      -16.94%
BenchmarkSiteBuilding/TOML,num_langs=3,num_root_sections=5,num_pages=1000,tags_per_page=5,shortcodes,render-4     203515478     169208775     -16.86%

benchmark                                                                                                         old allocs     new allocs     delta
BenchmarkSiteBuilding/TOML,num_langs=1,num_root_sections=5,num_pages=500,tags_per_page=5,shortcodes,render-4      532464         391539         -26.47%
BenchmarkSiteBuilding/TOML,num_langs=1,num_root_sections=5,num_pages=1000,tags_per_page=5,shortcodes,render-4     1056549        772702         -26.87%
BenchmarkSiteBuilding/TOML,num_langs=3,num_root_sections=5,num_pages=500,tags_per_page=5,shortcodes,render-4      555974         406630         -26.86%
BenchmarkSiteBuilding/TOML,num_langs=3,num_root_sections=5,num_pages=1000,tags_per_page=5,shortcodes,render-4     1086545        789922         -27.30%

benchmark                                                                                                         old bytes     new bytes     delta
BenchmarkSiteBuilding/TOML,num_langs=1,num_root_sections=5,num_pages=500,tags_per_page=5,shortcodes,render-4      53243246      43598155      -18.12%
BenchmarkSiteBuilding/TOML,num_langs=1,num_root_sections=5,num_pages=1000,tags_per_page=5,shortcodes,render-4     105811617     86087116      -18.64%
BenchmarkSiteBuilding/TOML,num_langs=3,num_root_sections=5,num_pages=500,tags_per_page=5,shortcodes,render-4      54558852      44545097      -18.35%
BenchmarkSiteBuilding/TOML,num_langs=3,num_root_sections=5,num_pages=1000,tags_per_page=5,shortcodes,render-4     106903858     86978413      -18.64%
```

Fixes #3651
Closes #3158
Fixes #1014
Closes #2021
Fixes #1240
Updates #3757

1 files changed, 0 insertions, 34 deletions

diff --git a/helpers/path_test.go b/helpers/path_test.go
index 8d895d762..bb5125034 100644
--- a/helpers/path_test.go
+++ b/helpers/path_test.go
@@ -638,40 +638,6 @@ func TestFileAndExt(t *testing.T) {
 
 }
 
-func TestGuessSection(t *testing.T) {
-	type test struct {
-		input, expected string
-	}
-
-	data := []test{
-		{"/", ""},
-		{"", ""},
-		{"/content", ""},
-		{"content/", ""},
-		{"/content/", ""}, // /content/ is a special case. It will never be the section
-		{"/blog", ""},
-		{"/blog/", "blog"},
-		{"blog", ""},
-		{"content/blog", ""},
-		{"/content/blog/", "blog"},
-		{"/content/blog", ""}, // Lack of trailing slash indicates 'blog' is not a directory.
-		{"content/blog/", "blog"},
-		{"/contents/myblog/", "contents"},
-		{"/contents/yourblog", "contents"},
-		{"/contents/ourblog/", "contents"},
-		{"/content/myblog/", "myblog"},
-		{"/content/yourblog", ""},
-		{"/content/ourblog/", "ourblog"},
-	}
-
-	for i, d := range data {
-		expected := GuessSection(filepath.FromSlash(d.input))
-		if d.expected != expected {
-			t.Errorf("Test %d failed. Expected %q got %q", i, d.expected, expected)
-		}
-	}
-}
-
 func TestPathPrep(t *testing.T) {
 
 }