docs, update required Lazarus version and warn if compiled with laz < 2.2

docs/build.md

@@ -8,7 +8,7 @@ Dexed is mostly programmed in Object Pascal, using the the [Lazarus development
 ## Pre-requisites
 
 * Git
-* [Download](http://lazarus.freepascal.org/index.php?page=downloads) and setup the latest Lazarus version (>= 2.0.10) and  FPC + FPC sources (= 3.2.0) for your platform.
+* [Download](http://lazarus.freepascal.org/index.php?page=downloads) and setup the latest Lazarus version (>= 2.2.0) and  FPC + FPC sources (= 3.2.2) for your platform.
     * Windows: the three packages are bundled in an installer.
     * Linux: the three packages must be downloaded and setup individually. It's recommended to download the packages from _SourceForge_ and not from the official repository of the distribution because they don't always propose the latest version.
 * [Download](https://github.com/ldc-developers/ldc/releases) and setup LDC2, the LLVM-based D compiler. It is used to compile the part of the IDE that's written in D, a library called _libdexed-d_. LDC2 binaries must be visible in the system PATH variable. Note that building _libdexed-d_ is automatic.

src/u_main.pas

@@ -1758,6 +1758,8 @@ begin
     DockMaster.MakeDockSite(Self, [akBottom], admrpChild);
     DockMaster.OnShowOptions := @ShowAnchorDockOptions;
     {$if lcl_fullversion < 2020000}
+    {$WARNING It is deprecated to use Lazarus 2.0.z to build dexed}
+    {$WARNING Support will be removed after Lazarus 2.2.2 release}
     DockMaster.HeaderStyle := adhsPoints;
     {$else}
     DockMaster.HeaderStyle := 'Points';
@@ -3764,6 +3766,8 @@ begin
 end;
 
 {$if lcl_fullversion < 2020000}
+{$WARNING It is deprecated to use Lazarus 2.0.z to build dexed}
+{$WARNING Support will be removed after Lazarus 2.2.2 release}
 procedure TMainForm.updateFloatingWidgetOnTop(onTop: boolean);
 var
   widg: TDexedWidget;

src/u_synmemo.pas

@@ -848,6 +848,8 @@ begin
     // - TextView visibility is increased so this is not the standard way of getting the infos.
 
     {$if lcl_fullversion < 2020000}
+    {$WARNING It is deprecated to use Lazarus 2.0.z to build dexed}
+    {$WARNING Support will be removed after Lazarus 2.2.2 release}
     start := fMemo.TextView.CollapsedLineForFoldAtLine(i);
     {$else}
     start := TSynEditFoldedView(fMemo.TextViewsManager.SynTextViewByClass[TSynEditFoldedView]).CollapsedLineForFoldAtLine(i);
@@ -885,6 +887,8 @@ begin
     if not itm.isCollapsed then
       continue;
     {$if lcl_fullversion < 2020000}
+    {$WARNING It is deprecated to use Lazarus 2.0.z to build dexed}
+    {$WARNING Support will be removed after Lazarus 2.2.2 release}
     fMemo.TextView.FoldAtLine(itm.lineIndex-1);
     {$else}
     TSynEditFoldedView(fMemo.TextViewsManager.SynTextViewByClass[TSynEditFoldedView]).FoldAtLine(itm.lineIndex-1);
@@ -1172,6 +1176,8 @@ begin
   fModified := false;
 
   {$if lcl_fullversion < 2020000}
+  {$WARNING It is deprecated to use Lazarus 2.0.z to build dexed}
+  {$WARNING Support will be removed after Lazarus 2.2.2 release}
   TextBuffer.AddNotifyHandler(senrUndoRedoAdded, @changeNotify);
   {$else}
   TextViewsManager.SynTextView[0].AddNotifyHandler(senrUndoRedoAdded, @changeNotify);

src/u_synmultiguttermarks.pas

@@ -95,6 +95,8 @@ begin
   aFirstCustomColumnIdx := 0;
   {$if lcl_fullversion < 2020000}
   i := FoldView.TextIndex[aScreenLine];
+  {$WARNING It is deprecated to use Lazarus 2.0.z to build dexed}
+  {$WARNING Support will be removed after Lazarus 2.2.2 release}
   {$else}
   aScreenLine := aScreenLine + ToIdx(GutterArea.TextArea.TopLine);
   i := ViewedTextBuffer.DisplayView.ViewToTextIndexEx(aScreenLine, iRange);