MODIFICATIONS DANO,AP, JAAP,ROBERT 23/5/08, 
INCLUDES SOME GENERAL BUGS AND IMPROVEMENTS
VERSION ENTERED INTO SUBVERSION AND TAGGED AS V12-EPSILON
WATCH OVERVIEW OF MODIFICATIONS BELOW
!
!params.f90
!
Introduced thetanaut keyword to allow to define computational grid in nautical convention (similar to SWAN)

keyword form --> sedimnet transport options: 1 = 
keyword carspan --> switch to use c instead of cg in instat=3
keyword rugauge --> observation point settings: 0 = normal observation point, 1 = observation point as runup gage (follows the runup)
keyword ting --> time interval output global variables
keyword tinp --> time interval output point variables
keyword tint --> min(tinp,ting)
keyword struct --> to include/define hard revetments
keyword A --> removed from params.txt
keyword par%Tm01 --> keyword is replaced by par%Trep (in all routines!!!)
keyword nspr--> no directional spreading in long waves0 
repaired factor 2 error in latitude conversion
keyword tintm for interval of writing time-averaged values (starts at tstart)
keyword sprdthr to set spectral values less than sprdthr*Sfmax to zero
keyword fcutoff to set hi-pass filter to filter out unrealistically low-frequency waves (e.g. in wave tanks)
!
!roelvink.f90
!
changed line 129
Qb = exp(-(Hb/H)**2.); 
into
Qb = exp(-(Hb/max(H,0.00001d0))**2)
!
!s.f90
!
allowed x and y grid to be defined in terms of world coordinates. Detect if this is the case by checking if 
difference between x(1,2) and x(1,1) is greater than 0.1 m; if so:
- copy x and y to xw and yw
- redefine xori, yori and alfa
- compute x and y

postponed conversion of theta0 until after this, because updated alfa is needed there.

modified computation of thetamin, thetamax, theta for case where thetanaut==1
!
!varoutput.f90
!
- many differences between versiealpha and xbeach_v11_alpha

- new difference: 
if (outputindex(19)==.true.) write(119,rec=itg)270-(s%thetamean*(180/par%px))
must be
if (outputindex(19)==.true.) write(119,rec=it)270-((s%thetamean+s%alfa)*(180/par%px))
Now output direction is degrees, nautical convention.
Same for all output angles
Added time-averaging 'on the fly' and outputting time-averages


!
!wave_stationary.f90
!
added at line 110:
    thetamean(1,:)=(sum(ee(1,:,:)*thet(1,:,:),2)/size(ee(1,:,:),2)) &
                  /(max(sum(ee(1,:,:),2),0.00001) /size(ee(1,:,:),2))
otherwise thetamean is not set at seaward boundary

removed tapering at approx. line 119

line 242: if (par%roller==1) then

changed (ascii/binary) format in reading/writing files to unformatted; direct acces

included (new) wave current interaction from Ad

changed expression for urms as was earlier done in wavetimestep.f90
Added initialization of H(i,:) to H(i-1,:) to improve shallow water behaviour

!!! TO DO reimplement wave current interaction into wave stationary, inside iteration loop !!!

!
!boundaryconditions.f90
!
changed (ascii/binary) format in reading/writing files to unformatted (which is also binary)

changed default back boundary condition to back=2, so it's absorbing acc.to Van Dongeren and Svendsen 97

fixed bug wrt writing timeseries

!
! waveparams.f90
!
changed (ascii/binary) format in reading/writing files to unformatted (which is also binary)

took out "floor" statement in waveparams.f90 because it caused a bug for
some tests.

build in option to switch between random seed and seed value of zero.

!
! nonhydrostatic.f90
!
removed from code. This routine is not yet ready to be used and is under development

!
! output.f90
!
removed from code; this routine is replaced by varoutput.f90

!
! flowtimestep.f90
!
removed nonhydrostatic statements
removed uv in variable declaration; uv is declared in s.f90
repaired bug in Coriolis in momentum equation that made it timestep depending

!
! morphevolution.f90
!
add new options for sediment transport; these options are in development and should be used with care

!
! flowtimestep.f90
!
new way of computing timestep