Use Apache's cxf-rt-frontend-jaxrs instead of JBoss' resteasy

Here's an alternative that uses Apache cxf instead of JBoss RestEasy to create the Rest client. This removes some dependencies, but introduces new ones (some of them strange, like geronimo javamail). You can use it in case it makes your CI config easier or something, otherwise just ignore it. It's not a big improvement, if at all, I think.

Here's the new set of dependencies:

[INFO] --- maven-dependency-plugin:2.1:tree (default-cli) @ xchange-bitstamp-standalone ---
[INFO] com.xeiam.xchange:xchange-bitstamp-standalone:jar:1.3.0-SNAPSHOT
[INFO] +- org.codehaus.jackson:jackson-jaxrs:jar:1.9.9:compile
[INFO] |  +- org.codehaus.jackson:jackson-core-asl:jar:1.9.7:compile (version managed from 1.9.9)
[INFO] |  \- org.codehaus.jackson:jackson-mapper-asl:jar:1.9.7:compile (version managed from 1.9.9)
[INFO] +- org.apache.cxf:cxf-rt-frontend-jaxrs:jar:2.6.4:compile
[INFO] |  +- org.apache.cxf:cxf-api:jar:2.6.4:compile
[INFO] |  |  +- org.codehaus.woodstox:woodstox-core-asl:jar:4.1.4:runtime
[INFO] |  |  |  \- org.codehaus.woodstox:stax2-api:jar:3.1.1:runtime
[INFO] |  |  +- org.apache.ws.xmlschema:xmlschema-core:jar:2.0.3:compile
[INFO] |  |  +- org.apache.geronimo.specs:geronimo-javamail_1.4_spec:jar:1.7.1:compile
[INFO] |  |  \- wsdl4j:wsdl4j:jar:1.6.2:compile
[INFO] |  +- org.apache.cxf:cxf-rt-core:jar:2.6.4:compile
[INFO] |  |  \- com.sun.xml.bind:jaxb-impl:jar:2.2.5.1:compile
[INFO] |  +- javax.ws.rs:jsr311-api:jar:1.1.1:compile
[INFO] |  +- org.apache.cxf:cxf-rt-bindings-xml:jar:2.6.4:compile
[INFO] |  \- org.apache.cxf:cxf-rt-transports-http:jar:2.6.4:compile
[INFO] +- org.hamcrest:hamcrest-library:jar:1.3:test
[INFO] |  \- org.hamcrest:hamcrest-core:jar:1.3:test
[INFO] \- junit:junit-dep:jar:4.10:test