Don't escape/quote command names in completion proposals

Fixes #76

spring-shell2-core/src/main/java/org/springframework/shell2/CompletionProposal.java

@@ -43,6 +43,12 @@ public class CompletionProposal {
 	 */
 	private String category;
 
+	/**
+	 * Whether the proposal should bypass escaping and quoting rules. This is useful for command proposals, which can
+	 * appear as true multi-word Strings.
+	 */
+	private boolean dontQuote = false;
+
 	public CompletionProposal(String value) {
 		this.value = this.displayText = value;
 	}
@@ -83,6 +89,15 @@ public class CompletionProposal {
 		return this;
 	}
 
+	public CompletionProposal dontQuote(boolean dontQuote) {
+		this.dontQuote = dontQuote;
+		return this;
+	}
+
+	public boolean dontQuote() {
+		return dontQuote;
+	}
+
 	@Override
 	public String toString() {
 		return value;

spring-shell2-core/src/main/java/org/springframework/shell2/Shell.java

@@ -172,6 +172,7 @@ public class Shell implements CommandRegistry {
 
 	private CompletionProposal toCompletionProposal(String command, MethodTarget methodTarget) {
 		return new CompletionProposal(command)
+			.dontQuote(true)
 			.category("Available commands")
 			.description(methodTarget.getHelp());
 	}

spring-shell2-core/src/main/java/org/springframework/shell2/jline/JLineShell.java

@@ -154,7 +154,7 @@ public class JLineShell {
 			List<CompletionProposal> proposals = shell.complete(context);
 			proposals.stream()
 				.map(p -> new Candidate(
-					cpl.emit(p.value()).toString(),
+					p.dontQuote() ? p.value() : cpl.emit(p.value()).toString(),
 					p.displayText(),
 					p.category(),
 					p.description(),