poputils 0.6.1

Reducing minimum R version

Reduced minimum R version required from 4.3.0 to 4.2.0, following the reduction in package rvec.

Discovered that function ex_to_lifetab_brass() was using a non-standard formula (applying logit to lx rather than 1 - lx). Hard-deprecated the function, and created a new function, e0_to_lifetab_logit(), that uses the correct formula.

Renamed iran_fertility to irn_fert.
Renamed nzmort to nzl_mort.
Renamed nzmort_rvec to nzl_mort_rvec.
Added function .intrinsic_growth_rate() to calculate growth rate associated with fertility, mortality schedules. Fairly low level - more user-friendly functions calling intrinsic_growth_rate() will be added in due course.
ex_to_lifetable_brass() returns a tibble rather than a base R data frame.
asfr argument for tfr() now defaults to asfr.

to_matrix() now uses rlang::all_of() with tidyselect arguments, to avoid deprecation warnings.

Modify function rr3 to use C code. (#30)
Modified tests for upcoming changes to package rvec (where random variant functions for discrete distributions will always return doubles).

Modify C++ function qx_to_ex() to avoid possible memory leekage found by valgrind.

If data already contains columns called "lx", "Lx", "dx", "ex", then lifetab() overwrites these columns, with a message, rather than creating new versions.
at argument to lifeexp() can now be a vector with length > 1. In this case, lifeexp() calculates life expectancy for each value (within each combination of the ‘by’ variables, if present.)
Added n_core argument to lifetab() and lifeexp(). Setting n_core to a value greater than 1 triggers parallel processing.
Added closed argument to check_age(), to check whether the oldest age group is closed.
Added function tfr() for calculating total fertility rates.
Extended vignette.

combine_age() previously not working properly if "to" is "five", and lower limit of youngest age group in x not divisible by 5.
ex_to_lifetab_brass() previously assumed, without checking that age groups were correctly ordered. ex_to_lifetab_brass() now automatically reorders them.

Previously calling lifetab() with value supplied for qx created a duplicate qx column in the result. The extra column has been removed.

Added at argument to lifeexp().
Removed mx column from output of lifetab() when calculated from mx (to be consistent with behaviour of lifetab() when calculated from qx.)

Removed stop(gettextf( style error messages, except in functions involving age (which will be superceded by package agetime.

Removed all uses of rvec::rvec.is.numeric(), in preparation for removing from rvec package.

Fixed bug in combine_age(). Previously giving wrong answers when last age group was closed.

Fixed “lifetab.cpp:455:16: runtime error: inf is outside the range of representable values of type ‘int’” - changed nx from int to double