C-a is now bound to inset-select-all

C-M-a is bound to the global "select all". The
reason for this change is that selecting an inset
is a more common operation that selecting an entire
document.

This patch is the result of discussion on #7727.

RELEASE-NOTES

@@ -30,6 +30,9 @@ The following LyX functions have been changed in 2.2:
 
 The following LyX key bindings have been changed in 2.2:
 
+- "C-a" is now bound to "inset-select-all" and "C-M-a" is now
+  bound to the old function (a command-sequence to select the
+  entire buffer).
 
 
 The following LyX documents have been moved in 2.2:

lib/bind/cua.bind

@@ -87,8 +87,8 @@ Format 2
 \bind "C-y"			"redo"
 \bind "C-S-Z"			"redo"
 
-\bind "C-a"			"command-sequence buffer-begin ; buffer-end-select"   # select all
-\bind "C-M-a"			"inset-select-all"
+\bind "C-M-a"			"command-sequence buffer-begin ; buffer-end-select"   # select all
+\bind "C-a"			"inset-select-all"
 
 \bind "C-S-E"			"changes-track"  # it's what MS Word uses
 \bind "~S-M-quotedbl"		"quote-insert single"

lib/bind/mac.bind

@@ -123,8 +123,8 @@ Format 2
 #  +: "Shift-Command-4"              # Capture a selection to a file
 #  +: "Shift-Control-Command-4"      # Capture a selection to the Clipboard
 #  +: "Command-A"                    # Highlight every item in a document or window, or all characters in a text field
-\bind "C-a"                          "command-sequence buffer-begin ; buffer-end-select"
-\bind "C-M-a"                        "inset-select-all"
+\bind "C-M-a"                        "command-sequence buffer-begin ; buffer-end-select"
+\bind "C-a"                          "inset-select-all"
 #  +: "Command-B"                    # Boldface the selected text or toggle boldfaced text on and off
 \bind "C-M-b"                        "font-boldsymbol"
 \bind "C-b"                          "font-bold"

lib/bind/sciword.bind

@@ -113,7 +113,8 @@ Format 2
 \bind "C-x"	"cut"
 \bind "C-z"	"undo"
 \bind "S-C-Z"	"redo"
-\bind "C-a"	"command-sequence buffer-begin ; buffer-end-select"   # select all
+\bind "C-a"	"inset-select-all"
+\bind "C-M-a"	"command-sequence buffer-begin ; buffer-end-select"   # select all
 
 
 # This combination makes an umlaut accent now.