Rework split package detection code

Allow packages to be split across projects which will be merged into a
single JAR file.

Make split package detection a dependency of the 'check' task. This
is idiomatic gradle as well as allowing the 'test' task (another
dependency of 'check') to be executed without split packages being
detected.

Omit the project spring-instructment-tomcat from the check on the basis
of SPR-10150.

Issues: SPR-9990, SPR-10150

Conflicts:

	build.gradle

build.gradle

@@ -8,14 +8,6 @@ buildscript {
 	}
 }
 
-configure(rootProject) {
-    apply plugin: org.springframework.build.gradle.SplitPackageDetectorPlugin
-
-	diagnoseSplitPackages {
-		inputDir = project.projectDir
-	}
-}
-
 configure(allprojects) { project ->
 	group = "org.springframework"
 	version = qualifyVersionIfNecessary(version)
@@ -761,13 +753,18 @@ configure(rootProject) {
 	apply plugin: "docbook-reference"
 	apply plugin: "groovy"
 	apply from: "${gradleScriptDir}/jdiff.gradle"
+    apply plugin: org.springframework.build.gradle.SplitPackageDetectorPlugin
 
-	reference {
+    reference {
 		sourceDir = file("src/reference/docbook")
 		pdfFilename = "spring-framework-reference.pdf"
 	}
 
-	// don"t publish the default jar for the root project
+    diagnoseSplitPackages {
+        projectsToScan = project.subprojects - project(":spring-instrument-tomcat") // SPR-10150
+    }
+
+    // don"t publish the default jar for the root project
 	configurations.archives.artifacts.clear()
 
 	dependencies { // for integration tests
@@ -791,6 +788,8 @@ configure(rootProject) {
 		testCompile("hsqldb:hsqldb:${hsqldbVersion}")
 	}
 
+    check.dependsOn diagnoseSplitPackages
+
 	task api(type: Javadoc) {
 		group = "Documentation"
 		description = "Generates aggregated Javadoc API documentation."