Implement Content search.

Modify existing search ui and non-tracker engine to:
- Allow toggling folder recursion, case sensitivity (for both
  file and content search).
- Content search can be plain text or a regular expression, if
  toggle is enabled
- If visible, the 'Hits' list view column will display of how many
  matches are in each file.
- Initial Support for text/plain files, pdf, ps, OpenDocument,
  exif (photo metadata) and id3 (mpeg metadata).
- text/plain support is native, the others are provided via 'search
  helpers, and additional formats are easily added. A search helper
  is defined by a desktop file (in a similar manner to thumbnailers) -
  it only needs to be able to parse a given file type and print the
  text to stdout.
- Multiple helpers can be defined for the same mimetype, and given
  priorities. If a helper is missing its executable, it is skipped,
  or a lower priority helper can be chosen.
- The tracker engine is unchanged, but can be made to take advantage
  of these changes to provide content search as well.
- Previous saved search functionality has been removed.

Author: mtwebster

config.h.meson.in

@@ -63,3 +63,5 @@
 // we just construct the definitons ourselves instead. Runtime
 // support is still checked at runtime (safely.) 
 #mesondefine NATIVE_STATX
+
+#mesondefine ENABLE_TRACKER

data/icons/hicolor/actions/scalable/nemo-recursive-search-symbolic.svg

@@ -29,6 +29,7 @@ publicIcons = [
   'hicolor/actions/scalable/nemo-horizontal-layout-wide-symbolic.svg',
   'hicolor/actions/scalable/nemo-vertical-layout-symbolic.svg',
   'hicolor/actions/scalable/nemo-vertical-layout-wide-symbolic.svg',
+  'hicolor/actions/scalable/nemo-recursive-search-symbolic.svg',
   'hicolor/devices/scalable/drive-removable-media-usb-symbolic.svg',
   'hicolor/status/48x48/progress-0.png',
   'hicolor/status/48x48/progress-10.png',

data/icons/meson.build

@@ -18,6 +18,7 @@ Build-Depends:
  libgirepository1.0-dev (>= 0.9.12),
  libglib2.0-dev (>= 2.45.7),
  libglib2.0-doc,
+ libgsf-1-dev,
  libgtk-3-dev (>= 3.10),
  libgtk-3-doc,
  libnotify-dev (>= 0.7.0),
@@ -98,6 +99,10 @@ Recommends:
  gvfs-fuse,
  librsvg2-common,
  nemo-fileroller,
+ poppler-utils,
+ exif,
+ id3,
+ odt2txt
 Suggests: eog, evince | pdf-viewer, totem | mp3-decoder, xdg-user-dirs
 Description: file manager and graphical shell for Cinnamon
  Nemo is the official file manager for the Cinnamon desktop. It allows

debian/control

@@ -0,0 +1,5 @@
+[Nemo Search Cat Helper]
+TryExec=exif
+Exec=exif -m %s
+MimeType=image/jpeg;image/png;image/gif;image/bmp;image/tiff
+Priority=100

files/usr/share/nemo/search-helpers/exif.nemo_search_helper

@@ -0,0 +1,5 @@
+[Nemo Search Cat Helper]
+TryExec=id3
+Exec=id3 -l %s
+MimeType=audio/mpeg
+Priority=100

files/usr/share/nemo/search-helpers/id3.nemo_search_helper

@@ -0,0 +1,5 @@
+[Nemo Search Cat Helper]
+TryExec=odt2txt
+Exec=odt2txt %s
+MimeType=application/vnd.oasis.opendocument.text;application/vnd.oasis.opendocument.spreadsheet;application/vnd.oasis.opendocument.presentation;application/vnd.oasis.opendocument.graphics;
+priority=100

files/usr/share/nemo/search-helpers/libreoffice.nemo_search_helper

@@ -0,0 +1,5 @@
+[Nemo Search Cat Helper]
+TryExec=pdf2txt
+Exec=pdf2txt %s
+MimeType=application/pdf;
+Priority=100

files/usr/share/nemo/search-helpers/pdf2txt.nemo_search_helper

@@ -0,0 +1,5 @@
+[Nemo Search Cat Helper]
+TryExec=pdftotext
+Exec=pdftotext %s -
+MimeType=application/pdf;
+Priority=200

files/usr/share/nemo/search-helpers/pdftotext.nemo_search_helper

@@ -0,0 +1,5 @@
+[Nemo Search Cat Helper]
+TryExec=ps2txt
+Exec=ps2txt %s
+MimeType=application/ps;
+Priority=100;

files/usr/share/nemo/search-helpers/ps2txt.nemo_search_helper

@@ -47,8 +47,6 @@
 		</placeholder>
 		<placeholder name="Global File Items Placeholder">
 			<menuitem name="Empty Trash" action="Empty Trash"/>
-			<menuitem name="Save Search" action="Save Search"/>
-			<menuitem name="Save Search As" action="Save Search As"/>
 		</placeholder>
 	</menu>
 	<menu action="Edit">