iSheets - HighQ 5.4 API improvements

Date Calculation 

Support for a new property donotcountweekendsonlycountmontofri added for date calculation column

• Get Columns API
• Add Column API
• Edit Column API
• Add Item API
• Edit Item API 

Join Column Condition

Join column condition logic implementation for the following API's

get single item, get all items

User lookup columns improvement

• Now includes a <fielddisplay> tag for <lookupuser> column in the "get all item" API. From this improvement the API client can decide which element of the user lookup they want to display.