Faster IcedTea builds

[Francis Kung]

>> I've just committed a change into the IcedTea repository providing a 
>> fast-build option: if you pass --enable-fast-build to configure, it will 
>> build with -O0 (instead of -O3) and will skip building all the javadoc.
>>
>> This speeds up the build by about 30-50% for me, which may be useful to 
>> those doing development work.
> 
> Isn't ccache a better option to make the build faster?

I wasn't familiar with ccache, but it does look very promising, yes! 
This sounds really cool... thanks for mentioning it =)

I'll open a ticket in the IcedTea bugzilla for it in case anyone wants 
to add this.

Francis