chore: begin v0.13.0-dev cycle

Version 0.12.0 -> 0.13.0-SNAPSHOT (Blaise.pas, project.xml) and COMPILER_ID
-> blaise-0.13.0-SNAPSHOT+bif2 (the .bif format is unchanged, so the +bif2
tag stays; the version prefix tracks the dev cycle).

compiler/src/main/pascal/Blaise.pas

@@ -40,7 +40,7 @@ type
   TBackend = TBackendKind;
 
 const
-  Version = '0.12.0';
+  Version = '0.13.0-SNAPSHOT';
   CompilerName = 'Blaise';
 
 { Build the --backend usage fragment from the registered drivers, with

compiler/src/main/pascal/uCompilerId.pas

@@ -24,7 +24,7 @@ unit uCompilerId;
 interface
 
 const
-  COMPILER_ID = 'blaise-0.12.0+bif2';
+  COMPILER_ID = 'blaise-0.13.0-SNAPSHOT+bif2';
 
 implementation
 

project.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project>
   <name>blaise</name>
-  <version>0.12.0</version>
+  <version>0.13.0-SNAPSHOT</version>
   <author>Graeme Geldenhuys</author>
   <license>Apache-2.0 WITH Swift-exception</license>