Add toolbar icons for LyX documentation

These icons are for lfuns that are not very interesting for users, but quite
often used when working on the LyX documentation. Now we can create a special
LyX documentation toolbar.

lib/Makefile.am

@@ -459,6 +459,7 @@ dist_images_DATA1X = \
 	images/href-insert.png \
 	images/hidetab.png \
 	images/index-insert.png \
+	images/info-insert.png \
 	images/info-insert_buffer_vcs-revision.png \
 	images/label-insert.png \
 	images/layout.png \
@@ -502,6 +503,11 @@ dist_images_DATA1X = \
 	images/reload.png \
 	images/script-insert_subscript.png \
 	images/script-insert_superscript.png \
+	images/specialchar-insert_latex.png \
+	images/specialchar-insert_latex2e.png \
+	images/specialchar-insert_lyx.png \
+	images/specialchar-insert_menu-separator.png \
+	images/specialchar-insert_tex.png \
 	images/spelling-continuously.png \
 	images/view-split_horizontal.png \
 	images/view-split_vertical.png \