Avoid embedding timestamps in the file paths for unzipped nar
dependencies.
Use getBaseVersion() instead of getVersion() when
constructing file paths for lib and include directories for nar
dependencies. Otherwise, Eclipse build configurations will break when a
new snapshot of a dependency is retrieved from a remote repo.

For example, if my project has the following dependency:
``` xml
<dependency>
  <groupdId>com.rccampbe</groupId>
  <artifactId>dep</artifactId>
  <version>1.0-SNAPSHOT</version>
  <type>nar</type>
</dependency>
```
then the nar plugin will establish include and lib directories for this
dependency. In the trunk version, those directories will vary based on
whether or not this snapshot dependency is resolved to a locally
installed artifact or a remotely retrieved artifact. Locally gets you
these directories:
```
target/nar/dep-1.0-SNAPSHOT-noarch
target/nar/dep-1.0-SNAPSHOT-{aol-identifier}
```
Remotely gets you embedded timestamps like this:
```
target/nar/dep-1.0-20131203.225113-noarch
target/nar/dep-1.0-20131203.225113-{aol-identifier}
```
Using getBaseVersion instead of getVersion prevents the timestamp
insertion which prevents unnecessary Eclipse build path maintenance.
Errors pop up, seemingly out of nowhere, when Maven automatically
retrieves the latest snapshot of a dependency and all of a sudden your
manually configured build path (with a timestamp in it) points to the
old, non-existent include and lib directories.