Some more user documentation improvements (compile problems and usage intro)


git-svn-id: svn://svn.code.sf.net/p/bochs/code/trunk@12299 6c8e4198-a580-4521-a02f-c9ae86df1db9
fixed compilation errors with FPU off

git-svn-id: svn://svn.code.sf.net/p/bochs/code/trunk@12300 6c8e4198-a580-4521-a02f-c9ae86df1db9