Trim the whitespaces in pom.xml's properties

Maven trims the whitespaces around pom.xml's properties by default.
Fixes #408

core/shared/src/main/scala/coursier/maven/Pom.scala

@@ -7,9 +7,18 @@ import scalaz._
 object Pom {
   import coursier.util.Xml._
 
+  /**
+    * Returns either a property's key-value pair or an error if the elem is not an element.
+    *
+    * This method trims all spaces, whereas Maven has an option to preserve them.
+    *
+    * @param elem a property element
+    * @return the key and the value of the property
+    * @see [[https://issues.apache.org/jira/browse/MNG-5380]]
+    */
   def property(elem: Node): String \/ (String, String) = {
     // Not matching with Text, which fails on scala-js if the property value has xml comments
-    if (elem.isElement) \/-(elem.label -> elem.textContent)
+    if (elem.isElement) \/-(elem.label -> elem.textContent.trim)
     else -\/(s"Can't parse property $elem")
   }
 

tests/shared/src/test/resources/resolutions/org.jboss.resteasy/resteasy-jaxrs/3.0.9.Final

@@ -0,0 +1,10 @@
+commons-codec:commons-codec:1.6:compile
+commons-io:commons-io:2.1:compile
+commons-logging:commons-logging:1.1.1:compile
+javax.activation:activation:1.1:compile
+net.jcip:jcip-annotations:1.0:compile
+org.apache.httpcomponents:httpclient:4.2.6:compile
+org.apache.httpcomponents:httpcore:4.2.5:compile
+org.jboss.resteasy:jaxrs-api:3.0.9.Final:compile
+org.jboss.resteasy:resteasy-jaxrs:3.0.9.Final:compile
+org.jboss.spec.javax.annotation:jboss-annotations-api_1.1_spec:1.0.1.Final:compile

tests/shared/src/test/scala/coursier/test/CentralTests.scala

@@ -455,6 +455,13 @@ object CentralTests extends TestSuite {
       )
     }
 
+    'ignoreWhitespaces - {
+      resolutionCheck(
+        Module("org.jboss.resteasy", "resteasy-jaxrs"),
+        "3.0.9.Final"
+      )
+    }
+
     'nd4jNative - {
       // In particular:
       // - uses OS-based activation,

tests/shared/src/test/scala/coursier/test/PomParsingTests.scala

@@ -194,6 +194,29 @@ object PomParsingTests extends TestSuite {
 
       assert(result == expected)
     }
+    'propertyWithSpaces{
+      val profileNode ="""
+        <profile>
+          <id>profile1</id>
+          <properties>
+            <first.prop>   value1   </first.prop>
+          </properties>
+        </profile>
+                       """
+
+      val expected = \/-(Profile(
+        "profile1",
+        None,
+        Profile.Activation(Nil),
+        Nil,
+        Nil,
+        Map("first.prop" -> "value1")
+      ))
+
+      val result = Pom.profile(xmlParse(profileNode).right.get)
+
+      assert(result == expected)
+    }
     'beFineWithCommentsInProperties{
       import scalaz._, Scalaz._