consolidate duplicate ConfigureOptionsAction classes

there were two nearly identical ConfigureOptionsAction classes defined
    * src/com/limegroup/gnutella/gui/actions/ConfigureOptionsAction.java
    * src/com/limegroup/gnutella/gui/options/ConfigureOptionsAction.java

the multi-argument constructor of the former was unused
its single-argument constructor was referencd only once in:
    * src/com/limegroup/gnutella/gui/shell/ShellAssociationManager.java

the single-argument constructor of the latter was unused
its multi-argument constructor was referencd three times in:
    * src/com/frostwire/gui/library/AbstractLibraryTableMediator.java
    * src/com/frostwire/gui/library/LibraryExplorer.java
    * src/com/frostwire/gui/library/LibraryPlaylists.java
Using a specific thread pool for VPN status checking.
With this thread pool, the native thread is created once at the beginning and is reused periodically in the refresh. With this we avoid the dynamic allocation of the native thread and we should alleviate the OOM exception that could be to a general lack of resources, not in our process, but in the entire OS.
6.0.2 build 1
hotfix changelog (6.0.2)
Update hr.po
Merge pull request #362 from win32re/patch-38

Update hr.po
hr.po typos
Updated jlibtorrent binaries.
Deleted eclipse file.
Update README.md

most importantly adding the preference for rebasing local commits over merging - but also filled it out a bit more with some relevant bits from the frostwire-android project README to make some points more explicit

* copied over some bits from the "coding standards" and "contribution guidelines" sections of the frostwire-android project

* removed "git pull" command from the "Getting the source" section - this followed immediatey after a "git clone" command which inherently pulls in the latest HEAD

* removed the paragraph mentioning the "eclipse.formatter.xml" file as it has apparently just been deleted from the repo

* minor cosmetic changes

regarding the windows instruction for setting environment variables in the "Build Requirements" section - (just as a note - this section was not altered) - im pretty sure that the java installer sets JAVA_HOME and adds it to the PATH automatically - CLASSPATH im not sure tho but the process is not at all similar unless one builds under something like cygwin or minGW - at least as i remember on XP setting environment variables persistently must be done via the gui "system properties"
Merge pull request #363 from bill-auger/update-readme

Update README.md
Merge pull request #361 from bill-auger/consolidate-duplicate-classes

consolidate duplicate ConfigureOptionsAction classes
exit gracefully for 32-bit hosts (issue #336)

* presents modal dialog warning for 32-bit hosts then exits
* added translation reference to lib/messagebundles/default.po
moved 64-bit sanity check into GUILoader class

* generalized GUILoader::displayError method (factored out hard-coded error messages)
* added I18n strings:
    * "Sorry, you need a 64-bit computer to use FrostWire on "
    * "Unsupported Platform"
    * "Fatal Error"

this is to prevent the main class from taking on any new dependencies allowing the splash screen to load faster

again many whitespace-only changes to make consistent the mixed tabs/spaces in:
    * src/com/limegroup/gnutella/gui/GUILoader.java

NOTE:
the 64-bit sanity check must preceed the try block in GUILoader::load because instantiating a swing component will itself throw many exceptions preventing it from being shown - whereby the original issue of the crash report dialog would be presented instead
Avoids com.frostwire.gui.theme.UiThreadingViolationException

Create the error alert window in the UI thread to avoid the ugly
UiThreadingViolationException you were getting.

Refactored that logic into a method of its own to keep GUILoader.load()
small, or in case we want to move that check elsewhere, it's easier.

Other cleanups.